Merge pull request #873 from toposware/hashconfig

Make hash functions generic

Cargo.toml

@@ -8,3 +8,12 @@ opt-level = 3
 
 [profile.bench]
 opt-level = 3
+
+
+[patch.crates-io]
+plonky2_evm = { path = "evm" }
+plonky2_field = { path = "field" }
+plonky2_maybe_rayon = { path = "maybe_rayon" }
+plonky2 = { path = "plonky2" }
+starky = { path = "starky" }
+plonky2_util = { path = "util" }

evm/src/cross_table_lookup.rs

@@ -8,6 +8,7 @@ use plonky2::field::packed::PackedField;
 use plonky2::field::polynomial::PolynomialValues;
 use plonky2::field::types::Field;
 use plonky2::hash::hash_types::RichField;
+use plonky2::hash::hashing::HashConfig;
 use plonky2::iop::ext_target::ExtensionTarget;
 use plonky2::iop::target::Target;
 use plonky2::plonk::circuit_builder::CircuitBuilder;
@@ -327,7 +328,10 @@ impl<'a, F: RichField + Extendable<D>, const D: usize>
         cross_table_lookups: &'a [CrossTableLookup<F>],
         ctl_challenges: &'a GrandProductChallengeSet<F>,
         num_permutation_zs: &[usize; NUM_TABLES],
-    ) -> [Vec<Self>; NUM_TABLES] {
+    ) -> [Vec<Self>; NUM_TABLES]
+    where
+        [(); C::HCO::WIDTH]:,
+    {
         let mut ctl_zs = proofs
             .iter()
             .zip(num_permutation_zs)

evm/src/fixed_recursive_verifier.rs

@@ -6,7 +6,7 @@ use plonky2::field::extension::Extendable;
 use plonky2::fri::FriParams;
 use plonky2::gates::noop::NoopGate;
 use plonky2::hash::hash_types::RichField;
-use plonky2::hash::hashing::SPONGE_WIDTH;
+use plonky2::hash::hashing::HashConfig;
 use plonky2::iop::challenger::RecursiveChallenger;
 use plonky2::iop::target::{BoolTarget, Target};
 use plonky2::iop::witness::{PartialWitness, WitnessWrite};
@@ -49,6 +49,7 @@ pub struct AllRecursiveCircuits<F, C, const D: usize>
 where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F>,
+    [(); C::HCO::WIDTH]:,
 {
     /// The EVM root circuit, which aggregates the (shrunk) per-table recursive proofs.
     pub root: RootCircuitData<F, C, D>,
@@ -111,13 +112,15 @@ impl<F, C, const D: usize> AllRecursiveCircuits<F, C, D>
 where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F> + 'static,
-    C::Hasher: AlgebraicHasher<F>,
+    C::Hasher: AlgebraicHasher<F, C::HCO>,
     [(); C::Hasher::HASH_SIZE]:,
     [(); CpuStark::<F, D>::COLUMNS]:,
     [(); KeccakStark::<F, D>::COLUMNS]:,
     [(); KeccakSpongeStark::<F, D>::COLUMNS]:,
     [(); LogicStark::<F, D>::COLUMNS]:,
     [(); MemoryStark::<F, D>::COLUMNS]:,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     /// Preprocess all recursive circuits used by the system.
     pub fn new(
@@ -184,11 +187,14 @@ where
         let recursive_proofs =
             core::array::from_fn(|i| builder.add_virtual_proof_with_pis(inner_common_data[i]));
         let pis: [_; NUM_TABLES] = core::array::from_fn(|i| {
-            PublicInputs::from_vec(&recursive_proofs[i].public_inputs, stark_config)
+            PublicInputs::<Target, C::HCO>::from_vec(
+                &recursive_proofs[i].public_inputs,
+                stark_config,
+            )
         });
         let index_verifier_data = core::array::from_fn(|_i| builder.add_virtual_target());
 
-        let mut challenger = RecursiveChallenger::<F, C::Hasher, D>::new(&mut builder);
+        let mut challenger = RecursiveChallenger::<F, C::HCO, C::Hasher, D>::new(&mut builder);
         for pi in &pis {
             for h in &pi.trace_cap {
                 challenger.observe_elements(h);
@@ -214,12 +220,12 @@ where
         }
 
         let state = challenger.compact(&mut builder);
-        for k in 0..SPONGE_WIDTH {
+        for k in 0..C::HCO::WIDTH {
             builder.connect(state[k], pis[0].challenger_state_before[k]);
         }
         // Check that the challenger state is consistent between proofs.
         for i in 1..NUM_TABLES {
-            for k in 0..SPONGE_WIDTH {
+            for k in 0..C::HCO::WIDTH {
                 builder.connect(
                     pis[i].challenger_state_before[k],
                     pis[i - 1].challenger_state_after[k],
@@ -267,7 +273,7 @@ where
         let cyclic_vk = builder.add_verifier_data_public_inputs();
 
         RootCircuitData {
-            circuit: builder.build(),
+            circuit: builder.build::<C>(),
             proof_with_pis: recursive_proofs,
             index_verifier_data,
             cyclic_vk,
@@ -471,6 +477,7 @@ struct RecursiveCircuitsForTable<F, C, const D: usize>
 where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F>,
+    [(); C::HCO::WIDTH]:,
 {
     /// A map from `log_2(height)` to a chain of shrinking recursion circuits starting at that
     /// height.
@@ -481,8 +488,10 @@ impl<F, C, const D: usize> RecursiveCircuitsForTable<F, C, D>
 where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F>,
-    C::Hasher: AlgebraicHasher<F>,
+    C::Hasher: AlgebraicHasher<F, C::HCO>,
     [(); C::Hasher::HASH_SIZE]:,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     fn new<S: Stark<F, D>>(
         table: Table,
@@ -533,6 +542,7 @@ struct RecursiveCircuitsForTableSize<F, C, const D: usize>
 where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F>,
+    [(); C::HCO::WIDTH]:,
 {
     initial_wrapper: StarkWrapperCircuit<F, C, D>,
     shrinking_wrappers: Vec<PlonkWrapperCircuit<F, C, D>>,
@@ -542,8 +552,10 @@ impl<F, C, const D: usize> RecursiveCircuitsForTableSize<F, C, D>
 where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F>,
-    C::Hasher: AlgebraicHasher<F>,
+    C::Hasher: AlgebraicHasher<F, C::HCO>,
     [(); C::Hasher::HASH_SIZE]:,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     fn new<S: Stark<F, D>>(
         table: Table,
@@ -584,7 +596,7 @@ where
             builder.verify_proof::<C>(&proof_with_pis_target, &last_vk, &last.common);
             builder.register_public_inputs(&proof_with_pis_target.public_inputs); // carry PIs forward
             add_common_recursion_gates(&mut builder);
-            let circuit = builder.build();
+            let circuit = builder.build::<C>();
 
             assert!(
                 circuit.common.degree_bits() < last_degree_bits,

evm/src/get_challenges.rs

@@ -1,6 +1,7 @@
 use plonky2::field::extension::Extendable;
 use plonky2::fri::proof::{FriProof, FriProofTarget};
 use plonky2::hash::hash_types::RichField;
+use plonky2::hash::hashing::HashConfig;
 use plonky2::iop::challenger::{Challenger, RecursiveChallenger};
 use plonky2::plonk::circuit_builder::CircuitBuilder;
 use plonky2::plonk::config::{AlgebraicHasher, GenericConfig};
@@ -13,14 +14,21 @@ use crate::permutation::{
 };
 use crate::proof::*;
 
-impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize> AllProof<F, C, D> {
+impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize> AllProof<F, C, D>
+where
+    [(); C::HCO::WIDTH]:,
+{
     /// Computes all Fiat-Shamir challenges used in the STARK proof.
     pub(crate) fn get_challenges(
         &self,
         all_stark: &AllStark<F, D>,
         config: &StarkConfig,
-    ) -> AllProofChallenges<F, D> {
+    ) -> AllProofChallenges<F, D>
-        let mut challenger = Challenger::<F, C::Hasher>::new();
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
+        let mut challenger = Challenger::<F, C::HCO, C::Hasher>::new();
 
         for proof in &self.stark_proofs {
             challenger.observe_cap(&proof.proof.trace_cap);
@@ -53,8 +61,12 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize> A
         &self,
         all_stark: &AllStark<F, D>,
         config: &StarkConfig,
-    ) -> AllChallengerState<F, D> {
+    ) -> AllChallengerState<F, C::HCO, D>
-        let mut challenger = Challenger::<F, C::Hasher>::new();
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
+        let mut challenger = Challenger::<F, C::HCO, C::Hasher>::new();
 
         for proof in &self.stark_proofs {
             challenger.observe_cap(&proof.proof.trace_cap);
@@ -94,11 +106,15 @@ where
     /// Computes all Fiat-Shamir challenges used in the STARK proof.
     pub(crate) fn get_challenges(
         &self,
-        challenger: &mut Challenger<F, C::Hasher>,
+        challenger: &mut Challenger<F, C::HCO, C::Hasher>,
         stark_use_permutation: bool,
         stark_permutation_batch_size: usize,
         config: &StarkConfig,
-    ) -> StarkProofChallenges<F, D> {
+    ) -> StarkProofChallenges<F, D>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         let degree_bits = self.recover_degree_bits(config);
 
         let StarkProof {
@@ -153,13 +169,15 @@ impl<const D: usize> StarkProofTarget<D> {
     pub(crate) fn get_challenges<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>>(
         &self,
         builder: &mut CircuitBuilder<F, D>,
-        challenger: &mut RecursiveChallenger<F, C::Hasher, D>,
+        challenger: &mut RecursiveChallenger<F, C::HCO, C::Hasher, D>,
         stark_use_permutation: bool,
         stark_permutation_batch_size: usize,
         config: &StarkConfig,
     ) -> StarkProofChallengesTarget<D>
     where
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
     {
         let StarkProofTarget {
             permutation_ctl_zs_cap,

evm/src/lib.rs

@@ -3,6 +3,7 @@
 #![allow(clippy::too_many_arguments)]
 #![allow(clippy::type_complexity)]
 #![allow(clippy::field_reassign_with_default)]
+#![allow(clippy::upper_case_acronyms)]
 #![feature(let_chains)]
 #![feature(generic_const_exprs)]
 

evm/src/permutation.rs

@@ -9,6 +9,7 @@ use plonky2::field::packed::PackedField;
 use plonky2::field::polynomial::PolynomialValues;
 use plonky2::field::types::Field;
 use plonky2::hash::hash_types::RichField;
+use plonky2::hash::hashing::HashConfig;
 use plonky2::iop::challenger::{Challenger, RecursiveChallenger};
 use plonky2::iop::ext_target::ExtensionTarget;
 use plonky2::iop::target::Target;
@@ -175,29 +176,38 @@ fn poly_product_elementwise<F: Field>(
     product
 }
 
-fn get_grand_product_challenge<F: RichField, H: Hasher<F>>(
+fn get_grand_product_challenge<F: RichField, HC: HashConfig, H: Hasher<F, HC>>(
-    challenger: &mut Challenger<F, H>,
+    challenger: &mut Challenger<F, HC, H>,
-) -> GrandProductChallenge<F> {
+) -> GrandProductChallenge<F>
+where
+    [(); HC::WIDTH]:,
+{
     let beta = challenger.get_challenge();
     let gamma = challenger.get_challenge();
     GrandProductChallenge { beta, gamma }
 }
 
-pub(crate) fn get_grand_product_challenge_set<F: RichField, H: Hasher<F>>(
+pub(crate) fn get_grand_product_challenge_set<F: RichField, HC: HashConfig, H: Hasher<F, HC>>(
-    challenger: &mut Challenger<F, H>,
+    challenger: &mut Challenger<F, HC, H>,
     num_challenges: usize,
-) -> GrandProductChallengeSet<F> {
+) -> GrandProductChallengeSet<F>
+where
+    [(); HC::WIDTH]:,
+{
     let challenges = (0..num_challenges)
         .map(|_| get_grand_product_challenge(challenger))
         .collect();
     GrandProductChallengeSet { challenges }
 }
 
-pub(crate) fn get_n_grand_product_challenge_sets<F: RichField, H: Hasher<F>>(
+pub(crate) fn get_n_grand_product_challenge_sets<F: RichField, HC: HashConfig, H: Hasher<F, HC>>(
-    challenger: &mut Challenger<F, H>,
+    challenger: &mut Challenger<F, HC, H>,
     num_challenges: usize,
     num_sets: usize,
-) -> Vec<GrandProductChallengeSet<F>> {
+) -> Vec<GrandProductChallengeSet<F>>
+where
+    [(); HC::WIDTH]:,
+{
     (0..num_sets)
         .map(|_| get_grand_product_challenge_set(challenger, num_challenges))
         .collect()
@@ -205,12 +215,16 @@ pub(crate) fn get_n_grand_product_challenge_sets<F: RichField, H: Hasher<F>>(
 
 fn get_grand_product_challenge_target<
     F: RichField + Extendable<D>,
-    H: AlgebraicHasher<F>,
+    HC: HashConfig,
+    H: AlgebraicHasher<F, HC>,
     const D: usize,
 >(
     builder: &mut CircuitBuilder<F, D>,
-    challenger: &mut RecursiveChallenger<F, H, D>,
+    challenger: &mut RecursiveChallenger<F, HC, H, D>,
-) -> GrandProductChallenge<Target> {
+) -> GrandProductChallenge<Target>
+where
+    [(); HC::WIDTH]:,
+{
     let beta = challenger.get_challenge(builder);
     let gamma = challenger.get_challenge(builder);
     GrandProductChallenge { beta, gamma }
@@ -218,13 +232,17 @@ fn get_grand_product_challenge_target<
 
 pub(crate) fn get_grand_product_challenge_set_target<
     F: RichField + Extendable<D>,
-    H: AlgebraicHasher<F>,
+    HC: HashConfig,
+    H: AlgebraicHasher<F, HC>,
     const D: usize,
 >(
     builder: &mut CircuitBuilder<F, D>,
-    challenger: &mut RecursiveChallenger<F, H, D>,
+    challenger: &mut RecursiveChallenger<F, HC, H, D>,
     num_challenges: usize,
-) -> GrandProductChallengeSet<Target> {
+) -> GrandProductChallengeSet<Target>
+where
+    [(); HC::WIDTH]:,
+{
     let challenges = (0..num_challenges)
         .map(|_| get_grand_product_challenge_target(builder, challenger))
         .collect();
@@ -233,14 +251,18 @@ pub(crate) fn get_grand_product_challenge_set_target<
 
 pub(crate) fn get_n_grand_product_challenge_sets_target<
     F: RichField + Extendable<D>,
-    H: AlgebraicHasher<F>,
+    HC: HashConfig,
+    H: AlgebraicHasher<F, HC>,
     const D: usize,
 >(
     builder: &mut CircuitBuilder<F, D>,
-    challenger: &mut RecursiveChallenger<F, H, D>,
+    challenger: &mut RecursiveChallenger<F, HC, H, D>,
     num_challenges: usize,
     num_sets: usize,
-) -> Vec<GrandProductChallengeSet<Target>> {
+) -> Vec<GrandProductChallengeSet<Target>>
+where
+    [(); HC::WIDTH]:,
+{
     (0..num_sets)
         .map(|_| get_grand_product_challenge_set_target(builder, challenger, num_challenges))
         .collect()

evm/src/proof.rs

@@ -7,7 +7,7 @@ use plonky2::fri::structure::{
     FriOpeningBatch, FriOpeningBatchTarget, FriOpenings, FriOpeningsTarget,
 };
 use plonky2::hash::hash_types::{MerkleCapTarget, RichField};
-use plonky2::hash::hashing::SPONGE_WIDTH;
+use plonky2::hash::hashing::HashConfig;
 use plonky2::hash::merkle_tree::MerkleCap;
 use plonky2::iop::ext_target::ExtensionTarget;
 use plonky2::iop::target::Target;
@@ -21,13 +21,19 @@ use crate::permutation::GrandProductChallengeSet;
 
 /// A STARK proof for each table, plus some metadata used to create recursive wrapper proofs.
 #[derive(Debug, Clone)]
-pub struct AllProof<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize> {
+pub struct AllProof<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
+where
+    [(); C::HCO::WIDTH]:,
+{
     pub stark_proofs: [StarkProofWithMetadata<F, C, D>; NUM_TABLES],
     pub(crate) ctl_challenges: GrandProductChallengeSet<F>,
     pub public_values: PublicValues,
 }
 
-impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize> AllProof<F, C, D> {
+impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize> AllProof<F, C, D>
+where
+    [(); C::HCO::WIDTH]:,
+{
     pub fn degree_bits(&self, config: &StarkConfig) -> [usize; NUM_TABLES] {
         core::array::from_fn(|i| self.stark_proofs[i].proof.recover_degree_bits(config))
     }
@@ -39,10 +45,13 @@ pub(crate) struct AllProofChallenges<F: RichField + Extendable<D>, const D: usiz
 }
 
 #[allow(unused)] // TODO: should be used soon
-pub(crate) struct AllChallengerState<F: RichField + Extendable<D>, const D: usize> {
+pub(crate) struct AllChallengerState<F: RichField + Extendable<D>, HC: HashConfig, const D: usize>
+where
+    [(); HC::WIDTH]:,
+{
     /// Sponge state of the challenger before starting each proof,
     /// along with the final state after all proofs are done. This final state isn't strictly needed.
-    pub states: [[F; SPONGE_WIDTH]; NUM_TABLES + 1],
+    pub states: [[F; HC::WIDTH]; NUM_TABLES + 1],
     pub ctl_challenges: GrandProductChallengeSet<F>,
 }
 
@@ -99,15 +108,15 @@ pub struct BlockMetadataTarget {
 #[derive(Debug, Clone)]
 pub struct StarkProof<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize> {
     /// Merkle cap of LDEs of trace values.
-    pub trace_cap: MerkleCap<F, C::Hasher>,
+    pub trace_cap: MerkleCap<F, C::HCO, C::Hasher>,
     /// Merkle cap of LDEs of permutation Z values.
-    pub permutation_ctl_zs_cap: MerkleCap<F, C::Hasher>,
+    pub permutation_ctl_zs_cap: MerkleCap<F, C::HCO, C::Hasher>,
     /// Merkle cap of LDEs of trace values.
-    pub quotient_polys_cap: MerkleCap<F, C::Hasher>,
+    pub quotient_polys_cap: MerkleCap<F, C::HCO, C::Hasher>,
     /// Purported values of each polynomial at the challenge point.
     pub openings: StarkOpeningSet<F, D>,
     /// A batch FRI argument for all openings.
-    pub opening_proof: FriProof<F, C::Hasher, D>,
+    pub opening_proof: FriProof<F, C::HCO, C::Hasher, D>,
 }
 
 /// A `StarkProof` along with some metadata about the initial Fiat-Shamir state, which is used when
@@ -117,8 +126,9 @@ pub struct StarkProofWithMetadata<F, C, const D: usize>
 where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F>,
+    [(); C::HCO::WIDTH]:,
 {
-    pub(crate) init_challenger_state: [F; SPONGE_WIDTH],
+    pub(crate) init_challenger_state: [F; C::HCO::WIDTH],
     pub(crate) proof: StarkProof<F, C, D>,
 }
 

evm/src/prover.rs

@@ -11,6 +11,7 @@ use plonky2::field::types::Field;
 use plonky2::field::zero_poly_coset::ZeroPolyOnCoset;
 use plonky2::fri::oracle::PolynomialBatch;
 use plonky2::hash::hash_types::RichField;
+use plonky2::hash::hashing::HashConfig;
 use plonky2::iop::challenger::Challenger;
 use plonky2::plonk::config::{GenericConfig, Hasher};
 use plonky2::timed;
@@ -50,12 +51,14 @@ pub fn prove<F, C, const D: usize>(
 where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F>,
-    [(); C::Hasher::HASH_SIZE]:,
     [(); CpuStark::<F, D>::COLUMNS]:,
     [(); KeccakStark::<F, D>::COLUMNS]:,
     [(); KeccakSpongeStark::<F, D>::COLUMNS]:,
     [(); LogicStark::<F, D>::COLUMNS]:,
     [(); MemoryStark::<F, D>::COLUMNS]:,
+    [(); C::Hasher::HASH_SIZE]:,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     let (proof, _outputs) = prove_with_outputs(all_stark, config, inputs, timing)?;
     Ok(proof)
@@ -78,6 +81,8 @@ where
     [(); KeccakSpongeStark::<F, D>::COLUMNS]:,
     [(); LogicStark::<F, D>::COLUMNS]:,
     [(); MemoryStark::<F, D>::COLUMNS]:,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     timed!(timing, "build kernel", Lazy::force(&KERNEL));
     let (traces, public_values, outputs) = timed!(
@@ -100,12 +105,14 @@ pub(crate) fn prove_with_traces<F, C, const D: usize>(
 where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F>,
-    [(); C::Hasher::HASH_SIZE]:,
     [(); CpuStark::<F, D>::COLUMNS]:,
     [(); KeccakStark::<F, D>::COLUMNS]:,
     [(); KeccakSpongeStark::<F, D>::COLUMNS]:,
     [(); LogicStark::<F, D>::COLUMNS]:,
     [(); MemoryStark::<F, D>::COLUMNS]:,
+    [(); C::Hasher::HASH_SIZE]:,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     let rate_bits = config.fri_config.rate_bits;
     let cap_height = config.fri_config.cap_height;
@@ -139,7 +146,7 @@ where
         .iter()
         .map(|c| c.merkle_tree.cap.clone())
         .collect::<Vec<_>>();
-    let mut challenger = Challenger::<F, C::Hasher>::new();
+    let mut challenger = Challenger::<F, C::HCO, C::Hasher>::new();
     for cap in &trace_caps {
         challenger.observe_cap(cap);
     }
@@ -182,7 +189,7 @@ fn prove_with_commitments<F, C, const D: usize>(
     trace_poly_values: [Vec<PolynomialValues<F>>; NUM_TABLES],
     trace_commitments: Vec<PolynomialBatch<F, C, D>>,
     ctl_data_per_table: [CtlData<F>; NUM_TABLES],
-    challenger: &mut Challenger<F, C::Hasher>,
+    challenger: &mut Challenger<F, C::HCO, C::Hasher>,
     timing: &mut TimingTree,
 ) -> Result<[StarkProofWithMetadata<F, C, D>; NUM_TABLES]>
 where
@@ -194,6 +201,8 @@ where
     [(); KeccakSpongeStark::<F, D>::COLUMNS]:,
     [(); LogicStark::<F, D>::COLUMNS]:,
     [(); MemoryStark::<F, D>::COLUMNS]:,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     let cpu_proof = timed!(
         timing,
@@ -276,15 +285,16 @@ pub(crate) fn prove_single_table<F, C, S, const D: usize>(
     trace_poly_values: &[PolynomialValues<F>],
     trace_commitment: &PolynomialBatch<F, C, D>,
     ctl_data: &CtlData<F>,
-    challenger: &mut Challenger<F, C::Hasher>,
+    challenger: &mut Challenger<F, C::HCO, C::Hasher>,
     timing: &mut TimingTree,
 ) -> Result<StarkProofWithMetadata<F, C, D>>
 where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F>,
     S: Stark<F, D>,
-    [(); C::Hasher::HASH_SIZE]:,
     [(); S::COLUMNS]:,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     let degree = trace_poly_values[0].len();
     let degree_bits = log2_strict(degree);

evm/src/recursive_verifier.rs

@@ -9,14 +9,14 @@ use plonky2::gates::exponentiation::ExponentiationGate;
 use plonky2::gates::gate::GateRef;
 use plonky2::gates::noop::NoopGate;
 use plonky2::hash::hash_types::RichField;
-use plonky2::hash::hashing::SPONGE_WIDTH;
+use plonky2::hash::hashing::HashConfig;
 use plonky2::iop::challenger::{Challenger, RecursiveChallenger};
 use plonky2::iop::ext_target::ExtensionTarget;
 use plonky2::iop::target::Target;
 use plonky2::iop::witness::{PartialWitness, Witness, WitnessWrite};
 use plonky2::plonk::circuit_builder::CircuitBuilder;
 use plonky2::plonk::circuit_data::{CircuitConfig, CircuitData, VerifierCircuitData};
-use plonky2::plonk::config::{AlgebraicHasher, GenericConfig, Hasher};
+use plonky2::plonk::config::{AlgebraicHasher, GenericConfig};
 use plonky2::plonk::proof::{ProofWithPublicInputs, ProofWithPublicInputsTarget};
 use plonky2::util::reducing::ReducingFactorTarget;
 use plonky2::with_context;
@@ -49,12 +49,15 @@ pub struct RecursiveAllProof<
     pub recursive_proofs: [ProofWithPublicInputs<F, C, D>; NUM_TABLES],
 }
 
-pub(crate) struct PublicInputs<T: Copy + Eq + PartialEq + Debug> {
+pub(crate) struct PublicInputs<T: Copy + Eq + PartialEq + Debug, HC: HashConfig>
+where
+    [(); HC::WIDTH]:,
+{
     pub(crate) trace_cap: Vec<Vec<T>>,
     pub(crate) ctl_zs_last: Vec<T>,
     pub(crate) ctl_challenges: GrandProductChallengeSet<T>,
-    pub(crate) challenger_state_before: [T; SPONGE_WIDTH],
+    pub(crate) challenger_state_before: [T; HC::WIDTH],
-    pub(crate) challenger_state_after: [T; SPONGE_WIDTH],
+    pub(crate) challenger_state_after: [T; HC::WIDTH],
 }
 
 /// Similar to the unstable `Iterator::next_chunk`. Could be replaced with that when it's stable.
@@ -66,7 +69,10 @@ fn next_chunk<T: Debug, const N: usize>(iter: &mut impl Iterator<Item = T>) -> [
         .expect("Not enough elements")
 }
 
-impl<T: Copy + Eq + PartialEq + Debug> PublicInputs<T> {
+impl<T: Copy + Eq + PartialEq + Debug, HC: HashConfig> PublicInputs<T, HC>
+where
+    [(); HC::WIDTH]:,
+{
     pub(crate) fn from_vec(v: &[T], config: &StarkConfig) -> Self {
         let mut iter = v.iter().copied();
         let trace_cap = (0..config.fri_config.num_cap_elements())
@@ -105,13 +111,17 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
         inner_config: &StarkConfig,
     ) -> Result<()>
     where
-        [(); C::Hasher::HASH_SIZE]:,
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
     {
         let pis: [_; NUM_TABLES] = core::array::from_fn(|i| {
-            PublicInputs::from_vec(&self.recursive_proofs[i].public_inputs, inner_config)
+            PublicInputs::<F, C::HCO>::from_vec(
+                &self.recursive_proofs[i].public_inputs,
+                inner_config,
+            )
         });
 
-        let mut challenger = Challenger::<F, C::Hasher>::new();
+        let mut challenger = Challenger::<F, C::HCO, C::Hasher>::new();
         for pi in &pis {
             for h in &pi.trace_cap {
                 challenger.observe_elements(h);
@@ -151,11 +161,12 @@ pub(crate) struct StarkWrapperCircuit<F, C, const D: usize>
 where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F>,
+    [(); C::HCO::WIDTH]:,
 {
     pub(crate) circuit: CircuitData<F, C, D>,
     pub(crate) stark_proof_target: StarkProofTarget<D>,
     pub(crate) ctl_challenges_target: GrandProductChallengeSet<Target>,
-    pub(crate) init_challenger_state_target: [Target; SPONGE_WIDTH],
+    pub(crate) init_challenger_state_target: [Target; C::HCO::WIDTH],
     pub(crate) zero_target: Target,
 }
 
@@ -163,7 +174,9 @@ impl<F, C, const D: usize> StarkWrapperCircuit<F, C, D>
 where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F>,
-    C::Hasher: AlgebraicHasher<F>,
+    C::Hasher: AlgebraicHasher<F, C::HCO>,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     pub(crate) fn prove(
         &self,
@@ -212,7 +225,9 @@ impl<F, C, const D: usize> PlonkWrapperCircuit<F, C, D>
 where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F>,
-    C::Hasher: AlgebraicHasher<F>,
+    C::Hasher: AlgebraicHasher<F, C::HCO>,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     pub(crate) fn prove(
         &self,
@@ -241,8 +256,9 @@ pub(crate) fn recursive_stark_circuit<
 ) -> StarkWrapperCircuit<F, C, D>
 where
     [(); S::COLUMNS]:,
-    [(); C::Hasher::HASH_SIZE]:,
+    C::Hasher: AlgebraicHasher<F, C::HCO>,
-    C::Hasher: AlgebraicHasher<F>,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     let mut builder = CircuitBuilder::<F, D>::new(circuit_config.clone());
     let zero_target = builder.zero();
@@ -281,7 +297,7 @@ where
 
     let init_challenger_state_target = core::array::from_fn(|_| builder.add_virtual_public_input());
     let mut challenger =
-        RecursiveChallenger::<F, C::Hasher, D>::from_state(init_challenger_state_target);
+        RecursiveChallenger::<F, C::HCO, C::Hasher, D>::from_state(init_challenger_state_target);
     let challenges = proof_target.get_challenges::<F, C>(
         &mut builder,
         &mut challenger,
@@ -345,8 +361,9 @@ fn verify_stark_proof_with_challenges_circuit<
     ctl_vars: &[CtlCheckVarsTarget<F, D>],
     inner_config: &StarkConfig,
 ) where
-    C::Hasher: AlgebraicHasher<F>,
+    C::Hasher: AlgebraicHasher<F, C::HCO>,
     [(); S::COLUMNS]:,
+    [(); C::HCO::WIDTH]:,
 {
     let zero = builder.zero();
     let one = builder.one_extension();
@@ -565,7 +582,7 @@ pub(crate) fn set_stark_proof_target<F, C: GenericConfig<D, F = F>, W, const D:
     zero: Target,
 ) where
     F: RichField + Extendable<D>,
-    C::Hasher: AlgebraicHasher<F>,
+    C::Hasher: AlgebraicHasher<F, C::HCO>,
     W: Witness<F>,
 {
     witness.set_cap_target(&proof_target.trace_cap, &proof.trace_cap);

evm/src/stark_testing.rs

@@ -3,10 +3,11 @@ use plonky2::field::extension::{Extendable, FieldExtension};
 use plonky2::field::polynomial::{PolynomialCoeffs, PolynomialValues};
 use plonky2::field::types::{Field, Sample};
 use plonky2::hash::hash_types::RichField;
+use plonky2::hash::hashing::HashConfig;
 use plonky2::iop::witness::{PartialWitness, WitnessWrite};
 use plonky2::plonk::circuit_builder::CircuitBuilder;
 use plonky2::plonk::circuit_data::CircuitConfig;
-use plonky2::plonk::config::{GenericConfig, Hasher};
+use plonky2::plonk::config::GenericConfig;
 use plonky2::util::transpose;
 use plonky2_util::{log2_ceil, log2_strict};
 
@@ -86,7 +87,8 @@ pub fn test_stark_circuit_constraints<
 ) -> Result<()>
 where
     [(); S::COLUMNS]:,
-    [(); C::Hasher::HASH_SIZE]:,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     // Compute native constraint evaluation on random values.
     let vars = StarkEvaluationVars {

evm/src/verifier.rs

@@ -5,7 +5,8 @@ use plonky2::field::extension::{Extendable, FieldExtension};
 use plonky2::field::types::Field;
 use plonky2::fri::verifier::verify_fri_proof;
 use plonky2::hash::hash_types::RichField;
-use plonky2::plonk::config::{GenericConfig, Hasher};
+use plonky2::hash::hashing::HashConfig;
+use plonky2::plonk::config::GenericConfig;
 use plonky2::plonk::plonk_common::reduce_with_powers;
 
 use crate::all_stark::{AllStark, Table};
@@ -36,7 +37,8 @@ where
     [(); KeccakSpongeStark::<F, D>::COLUMNS]:,
     [(); LogicStark::<F, D>::COLUMNS]:,
     [(); MemoryStark::<F, D>::COLUMNS]:,
-    [(); C::Hasher::HASH_SIZE]:,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     let AllProofChallenges {
         stark_challenges,
@@ -118,7 +120,7 @@ pub(crate) fn verify_stark_proof_with_challenges<
 ) -> Result<()>
 where
     [(); S::COLUMNS]:,
-    [(); C::Hasher::HASH_SIZE]:,
+    [(); C::HCO::WIDTH]:,
 {
     log::debug!("Checking proof: {}", type_name::<S>());
     validate_proof_shape(stark, proof, config, ctl_vars.len())?;
@@ -218,7 +220,6 @@ where
     C: GenericConfig<D, F = F>,
     S: Stark<F, D>,
     [(); S::COLUMNS]:,
-    [(); C::Hasher::HASH_SIZE]:,
 {
     let StarkProof {
         trace_cap,

evm/tests/add11_yml.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::upper_case_acronyms)]
+
 use std::collections::HashMap;
 use std::time::Duration;
 

evm/tests/basic_smart_contract.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::upper_case_acronyms)]
+
 use std::collections::HashMap;
 use std::time::Duration;
 

evm/tests/empty_txn_list.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::upper_case_acronyms)]
+
 use std::collections::HashMap;
 use std::time::Duration;
 

evm/tests/simple_transfer.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::upper_case_acronyms)]
+
 use std::collections::HashMap;
 use std::time::Duration;
 

plonky2/benches/hashing.rs

@@ -4,17 +4,18 @@ use criterion::{criterion_group, criterion_main, BatchSize, Criterion};
 use plonky2::field::goldilocks_field::GoldilocksField;
 use plonky2::field::types::Sample;
 use plonky2::hash::hash_types::{BytesHash, RichField};
-use plonky2::hash::hashing::SPONGE_WIDTH;
 use plonky2::hash::keccak::KeccakHash;
-use plonky2::hash::poseidon::Poseidon;
+use plonky2::hash::poseidon::{Poseidon, SPONGE_WIDTH};
-use plonky2::plonk::config::Hasher;
+use plonky2::plonk::config::{Hasher, KeccakHashConfig};
 use tynm::type_name;
 
 pub(crate) fn bench_keccak<F: RichField>(c: &mut Criterion) {
     c.bench_function("keccak256", |b| {
         b.iter_batched(
             || (BytesHash::<32>::rand(), BytesHash::<32>::rand()),
-            |(left, right)| <KeccakHash<32> as Hasher<F>>::two_to_one(left, right),
+            |(left, right)| {
+                <KeccakHash<32> as Hasher<F, KeccakHashConfig>>::two_to_one(left, right)
+            },
             BatchSize::SmallInput,
         )
     });

plonky2/benches/merkle.rs

@@ -1,17 +1,23 @@
+#![feature(generic_const_exprs)]
+
 mod allocator;
 
 use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion};
 use plonky2::field::goldilocks_field::GoldilocksField;
 use plonky2::hash::hash_types::RichField;
+use plonky2::hash::hashing::HashConfig;
 use plonky2::hash::keccak::KeccakHash;
 use plonky2::hash::merkle_tree::MerkleTree;
 use plonky2::hash::poseidon::PoseidonHash;
-use plonky2::plonk::config::Hasher;
+use plonky2::plonk::config::{Hasher, KeccakHashConfig, PoseidonHashConfig};
 use tynm::type_name;
 
 const ELEMS_PER_LEAF: usize = 135;
 
-pub(crate) fn bench_merkle_tree<F: RichField, H: Hasher<F>>(c: &mut Criterion) {
+pub(crate) fn bench_merkle_tree<F: RichField, HC: HashConfig, H: Hasher<F, HC>>(c: &mut Criterion)
+where
+    [(); HC::WIDTH]:,
+{
     let mut group = c.benchmark_group(&format!(
         "merkle-tree<{}, {}>",
         type_name::<F>(),
@@ -23,14 +29,14 @@ pub(crate) fn bench_merkle_tree<F: RichField, H: Hasher<F>>(c: &mut Criterion) {
         let size = 1 << size_log;
         group.bench_with_input(BenchmarkId::from_parameter(size), &size, |b, _| {
             let leaves = vec![F::rand_vec(ELEMS_PER_LEAF); size];
-            b.iter(|| MerkleTree::<F, H>::new(leaves.clone(), 0));
+            b.iter(|| MerkleTree::<F, HC, H>::new(leaves.clone(), 0));
         });
     }
 }
 
 fn criterion_benchmark(c: &mut Criterion) {
-    bench_merkle_tree::<GoldilocksField, PoseidonHash>(c);
+    bench_merkle_tree::<GoldilocksField, PoseidonHashConfig, PoseidonHash>(c);
-    bench_merkle_tree::<GoldilocksField, KeccakHash<25>>(c);
+    bench_merkle_tree::<GoldilocksField, KeccakHashConfig, KeccakHash<25>>(c);
 }
 
 criterion_group!(benches, criterion_benchmark);

plonky2/examples/bench_recursion.rs

@@ -3,6 +3,9 @@
 // put it in `src/bin/`, but then we wouldn't have access to
 // `[dev-dependencies]`.
 
+#![feature(generic_const_exprs)]
+#![allow(clippy::upper_case_acronyms)]
+
 use core::num::ParseIntError;
 use core::ops::RangeInclusive;
 use core::str::FromStr;
@@ -11,6 +14,7 @@ use anyhow::{anyhow, Context as _, Result};
 use log::{info, Level, LevelFilter};
 use plonky2::gates::noop::NoopGate;
 use plonky2::hash::hash_types::RichField;
+use plonky2::hash::hashing::HashConfig;
 use plonky2::iop::witness::{PartialWitness, WitnessWrite};
 use plonky2::plonk::circuit_builder::CircuitBuilder;
 use plonky2::plonk::circuit_data::{CircuitConfig, CommonCircuitData, VerifierOnlyCircuitData};
@@ -62,7 +66,11 @@ struct Options {
 fn dummy_proof<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>(
     config: &CircuitConfig,
     log2_size: usize,
-) -> Result<ProofTuple<F, C, D>> {
+) -> Result<ProofTuple<F, C, D>>
+where
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
+{
     // 'size' is in degree, but we want number of noop gates. A non-zero amount of padding will be added and size will be rounded to the next power of two. To hit our target size, we go just under the previous power of two and hope padding is less than half the proof.
     let num_dummy_gates = match log2_size {
         0 => return Err(anyhow!("size must be at least 1")),
@@ -81,7 +89,7 @@ fn dummy_proof<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D
     let inputs = PartialWitness::new();
 
     let mut timing = TimingTree::new("prove", Level::Debug);
-    let proof = prove(&data.prover_only, &data.common, inputs, &mut timing)?;
+    let proof = prove::<F, C, D>(&data.prover_only, &data.common, inputs, &mut timing)?;
     timing.print();
     data.verify(proof.clone())?;
 
@@ -99,7 +107,11 @@ fn recursive_proof<
     min_degree_bits: Option<usize>,
 ) -> Result<ProofTuple<F, C, D>>
 where
-    InnerC::Hasher: AlgebraicHasher<F>,
+    InnerC::Hasher: AlgebraicHasher<F, InnerC::HCO>,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
+    [(); InnerC::HCO::WIDTH]:,
+    [(); InnerC::HCI::WIDTH]:,
 {
     let (inner_proof, inner_vd, inner_cd) = inner;
     let mut builder = CircuitBuilder::<F, D>::new(config.clone());
@@ -128,7 +140,7 @@ where
     pw.set_verifier_data_target(&inner_data, inner_vd);
 
     let mut timing = TimingTree::new("prove", Level::Debug);
-    let proof = prove(&data.prover_only, &data.common, pw, &mut timing)?;
+    let proof = prove::<F, C, D>(&data.prover_only, &data.common, pw, &mut timing)?;
     timing.print();
 
     data.verify(proof.clone())?;
@@ -141,7 +153,11 @@ fn test_serialization<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>,
     proof: &ProofWithPublicInputs<F, C, D>,
     vd: &VerifierOnlyCircuitData<C, D>,
     cd: &CommonCircuitData<F, D>,
-) -> Result<()> {
+) -> Result<()>
+where
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
+{
     let proof_bytes = proof.to_bytes();
     info!("Proof length: {} bytes", proof_bytes.len());
     let proof_from_bytes = ProofWithPublicInputs::from_bytes(proof_bytes, cd)?;

plonky2/examples/factorial.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::upper_case_acronyms)]
+
 use anyhow::Result;
 use plonky2::field::types::Field;
 use plonky2::iop::witness::{PartialWitness, WitnessWrite};

plonky2/examples/fibonacci.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::upper_case_acronyms)]
+
 use anyhow::Result;
 use plonky2::field::types::Field;
 use plonky2::iop::witness::{PartialWitness, WitnessWrite};

plonky2/examples/square_root.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::upper_case_acronyms)]
+
 use core::marker::PhantomData;
 
 use anyhow::Result;

plonky2/src/fri/challenges.rs

@@ -5,16 +5,21 @@ use crate::fri::structure::{FriOpenings, FriOpeningsTarget};
 use crate::fri::FriConfig;
 use crate::gadgets::polynomial::PolynomialCoeffsExtTarget;
 use crate::hash::hash_types::{MerkleCapTarget, RichField};
+use crate::hash::hashing::HashConfig;
 use crate::hash::merkle_tree::MerkleCap;
 use crate::iop::challenger::{Challenger, RecursiveChallenger};
 use crate::iop::target::Target;
 use crate::plonk::circuit_builder::CircuitBuilder;
 use crate::plonk::config::{AlgebraicHasher, GenericConfig, Hasher};
 
-impl<F: RichField, H: Hasher<F>> Challenger<F, H> {
+impl<F: RichField, HCO: HashConfig, H: Hasher<F, HCO>> Challenger<F, HCO, H>
+where
+    [(); HCO::WIDTH]:,
+{
     pub fn observe_openings<const D: usize>(&mut self, openings: &FriOpenings<F, D>)
     where
         F: RichField + Extendable<D>,
+        [(); HCO::WIDTH]:,
     {
         for v in &openings.batches {
             self.observe_extension_elements(&v.values);
@@ -23,7 +28,7 @@ impl<F: RichField, H: Hasher<F>> Challenger<F, H> {
 
     pub fn fri_challenges<C: GenericConfig<D, F = F>, const D: usize>(
         &mut self,
-        commit_phase_merkle_caps: &[MerkleCap<F, C::Hasher>],
+        commit_phase_merkle_caps: &[MerkleCap<F, C::HCO, C::Hasher>],
         final_poly: &PolynomialCoeffs<F::Extension>,
         pow_witness: F,
         degree_bits: usize,
@@ -31,6 +36,8 @@ impl<F: RichField, H: Hasher<F>> Challenger<F, H> {
     ) -> FriChallenges<F, D>
     where
         F: RichField + Extendable<D>,
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
     {
         let num_fri_queries = config.num_query_rounds;
         let lde_size = 1 << (degree_bits + config.rate_bits);
@@ -41,7 +48,7 @@ impl<F: RichField, H: Hasher<F>> Challenger<F, H> {
         let fri_betas = commit_phase_merkle_caps
             .iter()
             .map(|cap| {
-                self.observe_cap(cap);
+                self.observe_cap::<C::HCO, C::Hasher>(cap);
                 self.get_extension_challenge::<D>()
             })
             .collect();
@@ -64,10 +71,15 @@ impl<F: RichField, H: Hasher<F>> Challenger<F, H> {
     }
 }
 
-impl<F: RichField + Extendable<D>, H: AlgebraicHasher<F>, const D: usize>
+impl<F: RichField + Extendable<D>, HCO: HashConfig, H: AlgebraicHasher<F, HCO>, const D: usize>
-    RecursiveChallenger<F, H, D>
+    RecursiveChallenger<F, HCO, H, D>
+where
+    [(); HCO::WIDTH]:,
 {
-    pub fn observe_openings(&mut self, openings: &FriOpeningsTarget<D>) {
+    pub fn observe_openings(&mut self, openings: &FriOpeningsTarget<D>)
+    where
+        [(); HCO::WIDTH]:,
+    {
         for v in &openings.batches {
             self.observe_extension_elements(&v.values);
         }

plonky2/src/fri/oracle.rs

@@ -14,6 +14,7 @@ use crate::fri::prover::fri_proof;
 use crate::fri::structure::{FriBatchInfo, FriInstanceInfo};
 use crate::fri::FriParams;
 use crate::hash::hash_types::RichField;
+use crate::hash::hashing::HashConfig;
 use crate::hash::merkle_tree::MerkleTree;
 use crate::iop::challenger::Challenger;
 use crate::plonk::config::GenericConfig;
@@ -29,7 +30,7 @@ pub const SALT_SIZE: usize = 4;
 pub struct PolynomialBatch<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
 {
     pub polynomials: Vec<PolynomialCoeffs<F>>,
-    pub merkle_tree: MerkleTree<F, C::Hasher>,
+    pub merkle_tree: MerkleTree<F, C::HCO, C::Hasher>,
     pub degree_log: usize,
     pub rate_bits: usize,
     pub blinding: bool,
@@ -46,7 +47,10 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
         cap_height: usize,
         timing: &mut TimingTree,
         fft_root_table: Option<&FftRootTable<F>>,
-    ) -> Self {
+    ) -> Self
+    where
+        [(); C::HCO::WIDTH]:,
+    {
         let coeffs = timed!(
             timing,
             "IFFT",
@@ -71,7 +75,10 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
         cap_height: usize,
         timing: &mut TimingTree,
         fft_root_table: Option<&FftRootTable<F>>,
-    ) -> Self {
+    ) -> Self
+    where
+        [(); C::HCO::WIDTH]:,
+    {
         let degree = polynomials[0].len();
         let lde_values = timed!(
             timing,
@@ -161,10 +168,14 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
     pub fn prove_openings(
         instance: &FriInstanceInfo<F, D>,
         oracles: &[&Self],
-        challenger: &mut Challenger<F, C::Hasher>,
+        challenger: &mut Challenger<F, C::HCO, C::Hasher>,
         fri_params: &FriParams,
         timing: &mut TimingTree,
-    ) -> FriProof<F, C::Hasher, D> {
+    ) -> FriProof<F, C::HCO, C::Hasher, D>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         assert!(D > 1, "Not implemented for D=1.");
         let alpha = challenger.get_extension_challenge::<D>();
         let mut alpha = ReducingFactor::new(alpha);

plonky2/src/fri/proof.rs

@@ -10,6 +10,7 @@ use crate::field::polynomial::PolynomialCoeffs;
 use crate::fri::FriParams;
 use crate::gadgets::polynomial::PolynomialCoeffsExtTarget;
 use crate::hash::hash_types::{MerkleCapTarget, RichField};
+use crate::hash::hashing::HashConfig;
 use crate::hash::merkle_proofs::{MerkleProof, MerkleProofTarget};
 use crate::hash::merkle_tree::MerkleCap;
 use crate::hash::path_compression::{compress_merkle_proofs, decompress_merkle_proofs};
@@ -22,9 +23,14 @@ use crate::plonk::proof::{FriInferredElements, ProofChallenges};
 /// Evaluations and Merkle proof produced by the prover in a FRI query step.
 #[derive(Serialize, Deserialize, Clone, Debug, Eq, PartialEq)]
 #[serde(bound = "")]
-pub struct FriQueryStep<F: RichField + Extendable<D>, H: Hasher<F>, const D: usize> {
+pub struct FriQueryStep<
+    F: RichField + Extendable<D>,
+    HC: HashConfig,
+    H: Hasher<F, HC>,
+    const D: usize,
+> {
     pub evals: Vec<F::Extension>,
-    pub merkle_proof: MerkleProof<F, H>,
+    pub merkle_proof: MerkleProof<F, HC, H>,
 }
 
 #[derive(Clone, Debug)]
@@ -37,11 +43,11 @@ pub struct FriQueryStepTarget<const D: usize> {
 /// before they are combined into a composition polynomial.
 #[derive(Serialize, Deserialize, Clone, Debug, Eq, PartialEq)]
 #[serde(bound = "")]
-pub struct FriInitialTreeProof<F: RichField, H: Hasher<F>> {
+pub struct FriInitialTreeProof<F: RichField, HC: HashConfig, H: Hasher<F, HC>> {
-    pub evals_proofs: Vec<(Vec<F>, MerkleProof<F, H>)>,
+    pub evals_proofs: Vec<(Vec<F>, MerkleProof<F, HC, H>)>,
 }
 
-impl<F: RichField, H: Hasher<F>> FriInitialTreeProof<F, H> {
+impl<F: RichField, HC: HashConfig, H: Hasher<F, HC>> FriInitialTreeProof<F, HC, H> {
     pub(crate) fn unsalted_eval(&self, oracle_index: usize, poly_index: usize, salted: bool) -> F {
         self.unsalted_evals(oracle_index, salted)[poly_index]
     }
@@ -76,9 +82,14 @@ impl FriInitialTreeProofTarget {
 /// Proof for a FRI query round.
 #[derive(Serialize, Deserialize, Clone, Debug, Eq, PartialEq)]
 #[serde(bound = "")]
-pub struct FriQueryRound<F: RichField + Extendable<D>, H: Hasher<F>, const D: usize> {
+pub struct FriQueryRound<
-    pub initial_trees_proof: FriInitialTreeProof<F, H>,
+    F: RichField + Extendable<D>,
-    pub steps: Vec<FriQueryStep<F, H, D>>,
+    HC: HashConfig,
+    H: Hasher<F, HC>,
+    const D: usize,
+> {
+    pub initial_trees_proof: FriInitialTreeProof<F, HC, H>,
+    pub steps: Vec<FriQueryStep<F, HC, H, D>>,
 }
 
 #[derive(Clone, Debug)]
@@ -90,22 +101,28 @@ pub struct FriQueryRoundTarget<const D: usize> {
 /// Compressed proof of the FRI query rounds.
 #[derive(Serialize, Deserialize, Clone, Debug, Eq, PartialEq)]
 #[serde(bound = "")]
-pub struct CompressedFriQueryRounds<F: RichField + Extendable<D>, H: Hasher<F>, const D: usize> {
+pub struct CompressedFriQueryRounds<
+    F: RichField + Extendable<D>,
+    HC: HashConfig,
+    H: Hasher<F, HC>,
+    const D: usize,
+> {
     /// Query indices.
     pub indices: Vec<usize>,
     /// Map from initial indices `i` to the `FriInitialProof` for the `i`th leaf.
-    pub initial_trees_proofs: HashMap<usize, FriInitialTreeProof<F, H>>,
+    pub initial_trees_proofs: HashMap<usize, FriInitialTreeProof<F, HC, H>>,
     /// For each FRI query step, a map from indices `i` to the `FriQueryStep` for the `i`th leaf.
-    pub steps: Vec<HashMap<usize, FriQueryStep<F, H, D>>>,
+    pub steps: Vec<HashMap<usize, FriQueryStep<F, HC, H, D>>>,
 }
 
 #[derive(Serialize, Deserialize, Clone, Debug, Eq, PartialEq)]
 #[serde(bound = "")]
-pub struct FriProof<F: RichField + Extendable<D>, H: Hasher<F>, const D: usize> {
+pub struct FriProof<F: RichField + Extendable<D>, HC: HashConfig, H: Hasher<F, HC>, const D: usize>
+{
     /// A Merkle cap for each reduced polynomial in the commit phase.
-    pub commit_phase_merkle_caps: Vec<MerkleCap<F, H>>,
+    pub commit_phase_merkle_caps: Vec<MerkleCap<F, HC, H>>,
     /// Query rounds proofs
-    pub query_round_proofs: Vec<FriQueryRound<F, H, D>>,
+    pub query_round_proofs: Vec<FriQueryRound<F, HC, H, D>>,
     /// The final polynomial in coefficient form.
     pub final_poly: PolynomialCoeffs<F::Extension>,
     /// Witness showing that the prover did PoW.
@@ -122,20 +139,31 @@ pub struct FriProofTarget<const D: usize> {
 
 #[derive(Serialize, Deserialize, Clone, Debug, Eq, PartialEq)]
 #[serde(bound = "")]
-pub struct CompressedFriProof<F: RichField + Extendable<D>, H: Hasher<F>, const D: usize> {
+pub struct CompressedFriProof<
+    F: RichField + Extendable<D>,
+    HC: HashConfig,
+    H: Hasher<F, HC>,
+    const D: usize,
+> {
     /// A Merkle cap for each reduced polynomial in the commit phase.
-    pub commit_phase_merkle_caps: Vec<MerkleCap<F, H>>,
+    pub commit_phase_merkle_caps: Vec<MerkleCap<F, HC, H>>,
     /// Compressed query rounds proof.
-    pub query_round_proofs: CompressedFriQueryRounds<F, H, D>,
+    pub query_round_proofs: CompressedFriQueryRounds<F, HC, H, D>,
     /// The final polynomial in coefficient form.
     pub final_poly: PolynomialCoeffs<F::Extension>,
     /// Witness showing that the prover did PoW.
     pub pow_witness: F,
 }
 
-impl<F: RichField + Extendable<D>, H: Hasher<F>, const D: usize> FriProof<F, H, D> {
+impl<F: RichField + Extendable<D>, HCO: HashConfig, H: Hasher<F, HCO>, const D: usize>
+    FriProof<F, HCO, H, D>
+{
     /// Compress all the Merkle paths in the FRI proof and remove duplicate indices.
-    pub fn compress(self, indices: &[usize], params: &FriParams) -> CompressedFriProof<F, H, D> {
+    pub fn compress(
+        self,
+        indices: &[usize],
+        params: &FriParams,
+    ) -> CompressedFriProof<F, HCO, H, D> {
         let FriProof {
             commit_phase_merkle_caps,
             query_round_proofs,
@@ -235,14 +263,19 @@ impl<F: RichField + Extendable<D>, H: Hasher<F>, const D: usize> FriProof<F, H,
     }
 }
 
-impl<F: RichField + Extendable<D>, H: Hasher<F>, const D: usize> CompressedFriProof<F, H, D> {
+impl<F: RichField + Extendable<D>, HCO: HashConfig, H: Hasher<F, HCO>, const D: usize>
+    CompressedFriProof<F, HCO, H, D>
+{
     /// Decompress all the Merkle paths in the FRI proof and reinsert duplicate indices.
     pub(crate) fn decompress(
         self,
         challenges: &ProofChallenges<F, D>,
         fri_inferred_elements: FriInferredElements<F, D>,
         params: &FriParams,
-    ) -> FriProof<F, H, D> {
+    ) -> FriProof<F, HCO, H, D>
+    where
+        [(); HCO::WIDTH]:,
+    {
         let CompressedFriProof {
             commit_phase_merkle_caps,
             query_round_proofs,

plonky2/src/fri/prover.rs

@@ -7,7 +7,7 @@ use crate::field::polynomial::{PolynomialCoeffs, PolynomialValues};
 use crate::fri::proof::{FriInitialTreeProof, FriProof, FriQueryRound, FriQueryStep};
 use crate::fri::{FriConfig, FriParams};
 use crate::hash::hash_types::RichField;
-use crate::hash::hashing::{PlonkyPermutation, SPONGE_RATE};
+use crate::hash::hashing::{HashConfig, PlonkyPermutation};
 use crate::hash::merkle_tree::MerkleTree;
 use crate::iop::challenger::Challenger;
 use crate::plonk::config::{GenericConfig, Hasher};
@@ -18,15 +18,19 @@ use crate::util::timing::TimingTree;
 
 /// Builds a FRI proof.
 pub fn fri_proof<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>(
-    initial_merkle_trees: &[&MerkleTree<F, C::Hasher>],
+    initial_merkle_trees: &[&MerkleTree<F, C::HCO, C::Hasher>],
     // Coefficients of the polynomial on which the LDT is performed. Only the first `1/rate` coefficients are non-zero.
     lde_polynomial_coeffs: PolynomialCoeffs<F::Extension>,
     // Evaluation of the polynomial on the large domain.
     lde_polynomial_values: PolynomialValues<F::Extension>,
-    challenger: &mut Challenger<F, C::Hasher>,
+    challenger: &mut Challenger<F, C::HCO, C::Hasher>,
     fri_params: &FriParams,
     timing: &mut TimingTree,
-) -> FriProof<F, C::Hasher, D> {
+) -> FriProof<F, C::HCO, C::Hasher, D>
+where
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
+{
     let n = lde_polynomial_values.len();
     assert_eq!(lde_polynomial_coeffs.len(), n);
 
@@ -62,16 +66,19 @@ pub fn fri_proof<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const
 }
 
 type FriCommitedTrees<F, C, const D: usize> = (
-    Vec<MerkleTree<F, <C as GenericConfig<D>>::Hasher>>,
+    Vec<MerkleTree<F, <C as GenericConfig<D>>::HCO, <C as GenericConfig<D>>::Hasher>>,
     PolynomialCoeffs<<F as Extendable<D>>::Extension>,
 );
 
 fn fri_committed_trees<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>(
     mut coeffs: PolynomialCoeffs<F::Extension>,
     mut values: PolynomialValues<F::Extension>,
-    challenger: &mut Challenger<F, C::Hasher>,
+    challenger: &mut Challenger<F, C::HCO, C::Hasher>,
     fri_params: &FriParams,
-) -> FriCommitedTrees<F, C, D> {
+) -> FriCommitedTrees<F, C, D>
+where
+    [(); C::HCO::WIDTH]:,
+{
     let mut trees = Vec::new();
 
     let mut shift = F::MULTIPLICATIVE_GROUP_GENERATOR;
@@ -84,7 +91,8 @@ fn fri_committed_trees<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>,
             .par_chunks(arity)
             .map(|chunk: &[F::Extension]| flatten(chunk))
             .collect();
-        let tree = MerkleTree::<F, C::Hasher>::new(chunked_values, fri_params.config.cap_height);
+        let tree =
+            MerkleTree::<F, C::HCO, C::Hasher>::new(chunked_values, fri_params.config.cap_height);
 
         challenger.observe_cap(&tree.cap);
         trees.push(tree);
@@ -113,9 +121,13 @@ fn fri_committed_trees<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>,
 
 /// Performs the proof-of-work (a.k.a. grinding) step of the FRI protocol. Returns the PoW witness.
 fn fri_proof_of_work<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>(
-    challenger: &mut Challenger<F, C::Hasher>,
+    challenger: &mut Challenger<F, C::HCO, C::Hasher>,
     config: &FriConfig,
-) -> F {
+) -> F
+where
+    [(); C::HCI::WIDTH]:,
+    [(); C::HCO::WIDTH]:,
+{
     let min_leading_zeros = config.proof_of_work_bits + (64 - F::order().bits()) as u32;
 
     // The easiest implementation would be repeatedly clone our Challenger. With each clone, we'd
@@ -126,7 +138,7 @@ fn fri_proof_of_work<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, c
     // since it stores vectors, which means allocations. We'd like a more compact state to clone.
     //
     // We know that a duplex will be performed right after we send the PoW witness, so we can ignore
-    // any output_buffer, which will be invalidated. We also know input_buffer.len() < SPONGE_WIDTH,
+    // any output_buffer, which will be invalidated. We also know input_buffer.len() < HCO::WIDTH,
     // an invariant of Challenger.
     //
     // We separate the duplex operation into two steps, one which can be performed now, and the
@@ -146,8 +158,10 @@ fn fri_proof_of_work<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, c
             let mut duplex_state = duplex_intermediate_state;
             duplex_state[witness_input_pos] = F::from_canonical_u64(candidate);
             duplex_state =
-                <<C as GenericConfig<D>>::Hasher as Hasher<F>>::Permutation::permute(duplex_state);
+                <<C as GenericConfig<D>>::Hasher as Hasher<F, C::HCO>>::Permutation::permute(
-            let pow_response = duplex_state[SPONGE_RATE - 1];
+                    duplex_state,
+                );
+            let pow_response = duplex_state[C::HCO::RATE - 1];
             let leading_zeros = pow_response.to_canonical_u64().leading_zeros();
             leading_zeros >= min_leading_zeros
         })
@@ -167,12 +181,15 @@ fn fri_prover_query_rounds<
     C: GenericConfig<D, F = F>,
     const D: usize,
 >(
-    initial_merkle_trees: &[&MerkleTree<F, C::Hasher>],
+    initial_merkle_trees: &[&MerkleTree<F, C::HCO, C::Hasher>],
-    trees: &[MerkleTree<F, C::Hasher>],
+    trees: &[MerkleTree<F, C::HCO, C::Hasher>],
-    challenger: &mut Challenger<F, C::Hasher>,
+    challenger: &mut Challenger<F, C::HCO, C::Hasher>,
     n: usize,
     fri_params: &FriParams,
-) -> Vec<FriQueryRound<F, C::Hasher, D>> {
+) -> Vec<FriQueryRound<F, C::HCO, C::Hasher, D>>
+where
+    [(); C::HCO::WIDTH]:,
+{
     challenger
         .get_n_challenges(fri_params.config.num_query_rounds)
         .into_par_iter()
@@ -188,11 +205,14 @@ fn fri_prover_query_round<
     C: GenericConfig<D, F = F>,
     const D: usize,
 >(
-    initial_merkle_trees: &[&MerkleTree<F, C::Hasher>],
+    initial_merkle_trees: &[&MerkleTree<F, C::HCO, C::Hasher>],
-    trees: &[MerkleTree<F, C::Hasher>],
+    trees: &[MerkleTree<F, C::HCO, C::Hasher>],
     mut x_index: usize,
     fri_params: &FriParams,
-) -> FriQueryRound<F, C::Hasher, D> {
+) -> FriQueryRound<F, C::HCO, C::Hasher, D>
+where
+    [(); C::HCO::WIDTH]:,
+{
     let mut query_steps = Vec::new();
     let initial_proof = initial_merkle_trees
         .iter()

plonky2/src/fri/recursive_verifier.rs

@@ -14,6 +14,7 @@ use crate::gates::coset_interpolation::CosetInterpolationGate;
 use crate::gates::gate::Gate;
 use crate::gates::random_access::RandomAccessGate;
 use crate::hash::hash_types::{MerkleCapTarget, RichField};
+use crate::hash::hashing::HashConfig;
 use crate::iop::ext_target::{flatten_target, ExtensionTarget};
 use crate::iop::target::{BoolTarget, Target};
 use crate::plonk::circuit_builder::CircuitBuilder;
@@ -107,7 +108,8 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         proof: &FriProofTarget<D>,
         params: &FriParams,
     ) where
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
+        [(); C::HCO::WIDTH]:,
     {
         if let Some(max_arity_bits) = params.max_arity_bits() {
             self.check_recursion_config(max_arity_bits);
@@ -175,13 +177,15 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         }
     }
 
-    fn fri_verify_initial_proof<H: AlgebraicHasher<F>>(
+    fn fri_verify_initial_proof<HC: HashConfig, H: AlgebraicHasher<F, HC>>(
         &mut self,
         x_index_bits: &[BoolTarget],
         proof: &FriInitialTreeProofTarget,
         initial_merkle_caps: &[MerkleCapTarget],
         cap_index: Target,
-    ) {
+    ) where
+        [(); HC::WIDTH]:,
+    {
         for (i, ((evals, merkle_proof), cap)) in proof
             .evals_proofs
             .iter()
@@ -191,7 +195,7 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
             with_context!(
                 self,
                 &format!("verify {i}'th initial Merkle proof"),
-                self.verify_merkle_proof_to_cap_with_cap_index::<H>(
+                self.verify_merkle_proof_to_cap_with_cap_index::<HC, H>(
                     evals.clone(),
                     x_index_bits,
                     cap_index,
@@ -258,7 +262,8 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         round_proof: &FriQueryRoundTarget<D>,
         params: &FriParams,
     ) where
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
+        [(); C::HCO::WIDTH]:,
     {
         let n_log = log2_strict(n);
 
@@ -272,7 +277,7 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         with_context!(
             self,
             "check FRI initial proof",
-            self.fri_verify_initial_proof::<C::Hasher>(
+            self.fri_verify_initial_proof::<C::HCO, C::Hasher>(
                 &x_index_bits,
                 &round_proof.initial_trees_proof,
                 initial_merkle_caps,
@@ -332,7 +337,7 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
             with_context!(
                 self,
                 "verify FRI round Merkle proof.",
-                self.verify_merkle_proof_to_cap_with_cap_index::<C::Hasher>(
+                self.verify_merkle_proof_to_cap_with_cap_index::<C::HCO, C::Hasher>(
                     flatten_target(evals),
                     &coset_index_bits,
                     cap_index,

plonky2/src/fri/validate_shape.rs

@@ -9,7 +9,7 @@ use crate::plonk::config::GenericConfig;
 use crate::plonk::plonk_common::salt_size;
 
 pub(crate) fn validate_fri_proof_shape<F, C, const D: usize>(
-    proof: &FriProof<F, C::Hasher, D>,
+    proof: &FriProof<F, C::HCO, C::Hasher, D>,
     instance: &FriInstanceInfo<F, D>,
     params: &FriParams,
 ) -> anyhow::Result<()>

plonky2/src/fri/verifier.rs

@@ -10,6 +10,7 @@ use crate::fri::structure::{FriBatchInfo, FriInstanceInfo, FriOpenings};
 use crate::fri::validate_shape::validate_fri_proof_shape;
 use crate::fri::{FriConfig, FriParams};
 use crate::hash::hash_types::RichField;
+use crate::hash::hashing::HashConfig;
 use crate::hash::merkle_proofs::verify_merkle_proof_to_cap;
 use crate::hash::merkle_tree::MerkleCap;
 use crate::plonk::config::{GenericConfig, Hasher};
@@ -58,18 +59,17 @@ pub(crate) fn fri_verify_proof_of_work<F: RichField + Extendable<D>, const D: us
     Ok(())
 }
 
-pub fn verify_fri_proof<
+pub fn verify_fri_proof<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>(
-    F: RichField + Extendable<D>,
-    C: GenericConfig<D, F = F>,
-    const D: usize,
->(
     instance: &FriInstanceInfo<F, D>,
     openings: &FriOpenings<F, D>,
     challenges: &FriChallenges<F, D>,
-    initial_merkle_caps: &[MerkleCap<F, C::Hasher>],
+    initial_merkle_caps: &[MerkleCap<F, C::HCO, C::Hasher>],
-    proof: &FriProof<F, C::Hasher, D>,
+    proof: &FriProof<F, C::HCO, C::Hasher, D>,
     params: &FriParams,
-) -> Result<()> {
+) -> Result<()>
+where
+    [(); C::HCO::WIDTH]:,
+{
     validate_fri_proof_shape::<F, C, D>(proof, instance, params)?;
 
     // Size of the LDE domain.
@@ -107,13 +107,16 @@ pub fn verify_fri_proof<
     Ok(())
 }
 
-fn fri_verify_initial_proof<F: RichField, H: Hasher<F>>(
+fn fri_verify_initial_proof<F: RichField, HC: HashConfig, H: Hasher<F, HC>>(
     x_index: usize,
-    proof: &FriInitialTreeProof<F, H>,
+    proof: &FriInitialTreeProof<F, HC, H>,
-    initial_merkle_caps: &[MerkleCap<F, H>],
+    initial_merkle_caps: &[MerkleCap<F, HC, H>],
-) -> Result<()> {
+) -> Result<()>
+where
+    [(); HC::WIDTH]:,
+{
     for ((evals, merkle_proof), cap) in proof.evals_proofs.iter().zip(initial_merkle_caps) {
-        verify_merkle_proof_to_cap::<F, H>(evals.clone(), x_index, cap, merkle_proof)?;
+        verify_merkle_proof_to_cap::<F, HC, H>(evals.clone(), x_index, cap, merkle_proof)?;
     }
 
     Ok(())
@@ -125,7 +128,7 @@ pub(crate) fn fri_combine_initial<
     const D: usize,
 >(
     instance: &FriInstanceInfo<F, D>,
-    proof: &FriInitialTreeProof<F, C::Hasher>,
+    proof: &FriInitialTreeProof<F, C::HCO, C::Hasher>,
     alpha: F::Extension,
     subgroup_x: F,
     precomputed_reduced_evals: &PrecomputedReducedOpenings<F, D>,
@@ -168,14 +171,17 @@ fn fri_verifier_query_round<
     instance: &FriInstanceInfo<F, D>,
     challenges: &FriChallenges<F, D>,
     precomputed_reduced_evals: &PrecomputedReducedOpenings<F, D>,
-    initial_merkle_caps: &[MerkleCap<F, C::Hasher>],
+    initial_merkle_caps: &[MerkleCap<F, C::HCO, C::Hasher>],
-    proof: &FriProof<F, C::Hasher, D>,
+    proof: &FriProof<F, C::HCO, C::Hasher, D>,
     mut x_index: usize,
     n: usize,
-    round_proof: &FriQueryRound<F, C::Hasher, D>,
+    round_proof: &FriQueryRound<F, C::HCO, C::Hasher, D>,
     params: &FriParams,
-) -> Result<()> {
+) -> Result<()>
-    fri_verify_initial_proof::<F, C::Hasher>(
+where
+    [(); C::HCO::WIDTH]:,
+{
+    fri_verify_initial_proof::<F, C::HCO, C::Hasher>(
         x_index,
         &round_proof.initial_trees_proof,
         initial_merkle_caps,
@@ -216,7 +222,7 @@ fn fri_verifier_query_round<
             challenges.fri_betas[i],
         );
 
-        verify_merkle_proof_to_cap::<F, C::Hasher>(
+        verify_merkle_proof_to_cap::<F, C::HCO, C::Hasher>(
             flatten(evals),
             coset_index,
             &proof.commit_phase_merkle_caps[i],

plonky2/src/fri/witness_util.rs

@@ -3,18 +3,20 @@ use itertools::Itertools;
 use crate::field::extension::Extendable;
 use crate::fri::proof::{FriProof, FriProofTarget};
 use crate::hash::hash_types::RichField;
+use crate::hash::hashing::HashConfig;
 use crate::iop::witness::WitnessWrite;
 use crate::plonk::config::AlgebraicHasher;
 
 /// Set the targets in a `FriProofTarget` to their corresponding values in a `FriProof`.
-pub fn set_fri_proof_target<F, W, H, const D: usize>(
+pub fn set_fri_proof_target<F, W, HC, H, const D: usize>(
     witness: &mut W,
     fri_proof_target: &FriProofTarget<D>,
-    fri_proof: &FriProof<F, H, D>,
+    fri_proof: &FriProof<F, HC, H, D>,
 ) where
     F: RichField + Extendable<D>,
     W: WitnessWrite<F> + ?Sized,
-    H: AlgebraicHasher<F>,
+    HC: HashConfig,
+    H: AlgebraicHasher<F, HC>,
 {
     witness.set_target(fri_proof_target.pow_witness, fri_proof.pow_witness);
 

plonky2/src/gadgets/hash.rs

@@ -1,27 +1,27 @@
 use crate::field::extension::Extendable;
 use crate::hash::hash_types::RichField;
-use crate::hash::hashing::SPONGE_WIDTH;
+use crate::hash::hashing::HashConfig;
 use crate::iop::target::{BoolTarget, Target};
 use crate::plonk::circuit_builder::CircuitBuilder;
 use crate::plonk::config::AlgebraicHasher;
 
 impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
-    pub fn permute<H: AlgebraicHasher<F>>(
+    pub fn permute<HC: HashConfig, H: AlgebraicHasher<F, HC>>(
         &mut self,
-        inputs: [Target; SPONGE_WIDTH],
+        inputs: [Target; HC::WIDTH],
-    ) -> [Target; SPONGE_WIDTH] {
+    ) -> [Target; HC::WIDTH] {
         // We don't want to swap any inputs, so set that wire to 0.
         let _false = self._false();
-        self.permute_swapped::<H>(inputs, _false)
+        self.permute_swapped::<HC, H>(inputs, _false)
     }
 
     /// Conditionally swap two chunks of the inputs (useful in verifying Merkle proofs), then apply
     /// a cryptographic permutation.
-    pub(crate) fn permute_swapped<H: AlgebraicHasher<F>>(
+    pub(crate) fn permute_swapped<HC: HashConfig, H: AlgebraicHasher<F, HC>>(
         &mut self,
-        inputs: [Target; SPONGE_WIDTH],
+        inputs: [Target; HC::WIDTH],
         swap: BoolTarget,
-    ) -> [Target; SPONGE_WIDTH] {
+    ) -> [Target; HC::WIDTH] {
         H::permute_swapped(inputs, swap, self)
     }
 }

plonky2/src/gates/gate_testing.rs

@@ -8,6 +8,7 @@ use crate::field::polynomial::{PolynomialCoeffs, PolynomialValues};
 use crate::field::types::{Field, Sample};
 use crate::gates::gate::Gate;
 use crate::hash::hash_types::{HashOut, RichField};
+use crate::hash::hashing::HashConfig;
 use crate::iop::witness::{PartialWitness, WitnessWrite};
 use crate::plonk::circuit_builder::CircuitBuilder;
 use crate::plonk::circuit_data::CircuitConfig;
@@ -93,7 +94,11 @@ pub fn test_eval_fns<
     const D: usize,
 >(
     gate: G,
-) -> Result<()> {
+) -> Result<()>
+where
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
+{
     // Test that `eval_unfiltered` and `eval_unfiltered_base` are coherent.
     let wires_base = F::rand_vec(gate.num_wires());
     let constants_base = F::rand_vec(gate.num_constants());
@@ -159,5 +164,5 @@ pub fn test_eval_fns<
 
     let data = builder.build::<C>();
     let proof = data.prove(pw)?;
-    verify(proof, &data.verifier_only, &data.common)
+    verify::<F, C, D>(proof, &data.verifier_only, &data.common)
 }

plonky2/src/gates/poseidon.rs

@@ -10,9 +10,8 @@ use crate::gates::gate::Gate;
 use crate::gates::poseidon_mds::PoseidonMdsGate;
 use crate::gates::util::StridedConstraintConsumer;
 use crate::hash::hash_types::RichField;
-use crate::hash::hashing::SPONGE_WIDTH;
 use crate::hash::poseidon;
-use crate::hash::poseidon::Poseidon;
+use crate::hash::poseidon::{Poseidon, SPONGE_WIDTH};
 use crate::iop::ext_target::ExtensionTarget;
 use crate::iop::generator::{GeneratedValues, SimpleGenerator, WitnessGenerator};
 use crate::iop::target::Target;
@@ -510,8 +509,7 @@ mod tests {
     use crate::field::types::Field;
     use crate::gates::gate_testing::{test_eval_fns, test_low_degree};
     use crate::gates::poseidon::PoseidonGate;
-    use crate::hash::hashing::SPONGE_WIDTH;
+    use crate::hash::poseidon::{Poseidon, SPONGE_WIDTH};
-    use crate::hash::poseidon::Poseidon;
     use crate::iop::generator::generate_partial_witness;
     use crate::iop::wire::Wire;
     use crate::iop::witness::{PartialWitness, Witness, WitnessWrite};

plonky2/src/gates/poseidon_mds.rs

@@ -11,8 +11,7 @@ use crate::field::types::Field;
 use crate::gates::gate::Gate;
 use crate::gates::util::StridedConstraintConsumer;
 use crate::hash::hash_types::RichField;
-use crate::hash::hashing::SPONGE_WIDTH;
+use crate::hash::poseidon::{Poseidon, SPONGE_WIDTH};
-use crate::hash::poseidon::Poseidon;
 use crate::iop::ext_target::{ExtensionAlgebraTarget, ExtensionTarget};
 use crate::iop::generator::{GeneratedValues, SimpleGenerator, WitnessGenerator};
 use crate::iop::target::Target;

plonky2/src/hash/hashing.rs

@@ -1,6 +1,7 @@
 //! Concrete instantiation of a hash function.
 
 use alloc::vec::Vec;
+use core::fmt::Debug;
 
 use crate::field::extension::Extendable;
 use crate::hash::hash_types::{HashOut, HashOutTarget, RichField};
@@ -8,62 +9,81 @@ use crate::iop::target::Target;
 use crate::plonk::circuit_builder::CircuitBuilder;
 use crate::plonk::config::AlgebraicHasher;
 
-pub(crate) const SPONGE_RATE: usize = 8;
+pub trait HashConfig: Clone + Debug + Eq + PartialEq {
-pub(crate) const SPONGE_CAPACITY: usize = 4;
+    const RATE: usize;
-pub const SPONGE_WIDTH: usize = SPONGE_RATE + SPONGE_CAPACITY;
+    const WIDTH: usize;
+}
 
 impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
-    pub fn hash_or_noop<H: AlgebraicHasher<F>>(&mut self, inputs: Vec<Target>) -> HashOutTarget {
+    pub fn hash_or_noop<HC: HashConfig, H: AlgebraicHasher<F, HC>>(
+        &mut self,
+        inputs: Vec<Target>,
+    ) -> HashOutTarget
+    where
+        [(); HC::WIDTH]:,
+    {
         let zero = self.zero();
         if inputs.len() <= 4 {
             HashOutTarget::from_partial(&inputs, zero)
         } else {
-            self.hash_n_to_hash_no_pad::<H>(inputs)
+            self.hash_n_to_hash_no_pad::<HC, H>(inputs)
         }
     }
 
-    pub fn hash_n_to_hash_no_pad<H: AlgebraicHasher<F>>(
+    pub fn hash_n_to_hash_no_pad<HC: HashConfig, H: AlgebraicHasher<F, HC>>(
         &mut self,
         inputs: Vec<Target>,
-    ) -> HashOutTarget {
+    ) -> HashOutTarget
-        HashOutTarget::from_vec(self.hash_n_to_m_no_pad::<H>(inputs, 4))
+    where
+        [(); HC::WIDTH]:,
+    {
+        HashOutTarget::from_vec(self.hash_n_to_m_no_pad::<HC, H>(inputs, 4))
     }
 
-    pub fn hash_n_to_m_no_pad<H: AlgebraicHasher<F>>(
+    pub fn hash_n_to_m_no_pad<HC: HashConfig, H: AlgebraicHasher<F, HC>>(
         &mut self,
         inputs: Vec<Target>,
         num_outputs: usize,
-    ) -> Vec<Target> {
+    ) -> Vec<Target>
+    where
+        [(); HC::WIDTH]:,
+    {
         let zero = self.zero();
 
-        let mut state = [zero; SPONGE_WIDTH];
+        let mut state = [zero; HC::WIDTH];
 
         // Absorb all input chunks.
-        for input_chunk in inputs.chunks(SPONGE_RATE) {
+        for input_chunk in inputs.chunks(HC::RATE) {
             // Overwrite the first r elements with the inputs. This differs from a standard sponge,
             // where we would xor or add in the inputs. This is a well-known variant, though,
             // sometimes called "overwrite mode".
             state[..input_chunk.len()].copy_from_slice(input_chunk);
-            state = self.permute::<H>(state);
+            state = self.permute::<HC, H>(state);
         }
 
         // Squeeze until we have the desired number of outputs.
         let mut outputs = Vec::with_capacity(num_outputs);
         loop {
-            for i in 0..SPONGE_RATE {
+            for i in 0..HC::RATE {
                 outputs.push(state[i]);
                 if outputs.len() == num_outputs {
                     return outputs;
                 }
             }
-            state = self.permute::<H>(state);
+            state = self.permute::<HC, H>(state);
         }
     }
 }
 
 /// A one-way compression function which takes two ~256 bit inputs and returns a ~256 bit output.
-pub fn compress<F: RichField, P: PlonkyPermutation<F>>(x: HashOut<F>, y: HashOut<F>) -> HashOut<F> {
+pub fn compress<F: RichField, HC: HashConfig, P: PlonkyPermutation<F, HC>>(
-    let mut perm_inputs = [F::ZERO; SPONGE_WIDTH];
+    x: HashOut<F>,
+    y: HashOut<F>,
+) -> HashOut<F>
+where
+    [(); HC::WIDTH]:,
+{
+    let mut perm_inputs = [F::ZERO; HC::WIDTH];
     perm_inputs[..4].copy_from_slice(&x.elements);
     perm_inputs[4..8].copy_from_slice(&y.elements);
     HashOut {
@@ -72,20 +92,25 @@ pub fn compress<F: RichField, P: PlonkyPermutation<F>>(x: HashOut<F>, y: HashOut
 }
 
 /// Permutation that can be used in the sponge construction for an algebraic hash.
-pub trait PlonkyPermutation<F: RichField> {
+pub trait PlonkyPermutation<F: RichField, HC: HashConfig> {
-    fn permute(input: [F; SPONGE_WIDTH]) -> [F; SPONGE_WIDTH];
+    fn permute(input: [F; HC::WIDTH]) -> [F; HC::WIDTH]
+    where
+        [(); HC::WIDTH]:;
 }
 
 /// Hash a message without any padding step. Note that this can enable length-extension attacks.
 /// However, it is still collision-resistant in cases where the input has a fixed length.
-pub fn hash_n_to_m_no_pad<F: RichField, P: PlonkyPermutation<F>>(
+pub fn hash_n_to_m_no_pad<F: RichField, HC: HashConfig, P: PlonkyPermutation<F, HC>>(
     inputs: &[F],
     num_outputs: usize,
-) -> Vec<F> {
+) -> Vec<F>
-    let mut state = [F::ZERO; SPONGE_WIDTH];
+where
+    [(); HC::WIDTH]:,
+{
+    let mut state = [F::ZERO; HC::WIDTH];
 
     // Absorb all input chunks.
-    for input_chunk in inputs.chunks(SPONGE_RATE) {
+    for input_chunk in inputs.chunks(HC::RATE) {
         state[..input_chunk.len()].copy_from_slice(input_chunk);
         state = P::permute(state);
     }
@@ -93,7 +118,7 @@ pub fn hash_n_to_m_no_pad<F: RichField, P: PlonkyPermutation<F>>(
     // Squeeze until we have the desired number of outputs.
     let mut outputs = Vec::new();
     loop {
-        for &item in state.iter().take(SPONGE_RATE) {
+        for &item in state.iter().take(HC::RATE) {
             outputs.push(item);
             if outputs.len() == num_outputs {
                 return outputs;
@@ -103,6 +128,11 @@ pub fn hash_n_to_m_no_pad<F: RichField, P: PlonkyPermutation<F>>(
     }
 }
 
-pub fn hash_n_to_hash_no_pad<F: RichField, P: PlonkyPermutation<F>>(inputs: &[F]) -> HashOut<F> {
+pub fn hash_n_to_hash_no_pad<F: RichField, HC: HashConfig, P: PlonkyPermutation<F, HC>>(
-    HashOut::from_vec(hash_n_to_m_no_pad::<F, P>(inputs, 4))
+    inputs: &[F],
+) -> HashOut<F>
+where
+    [(); HC::WIDTH]:,
+{
+    HashOut::from_vec(hash_n_to_m_no_pad::<F, HC, P>(inputs, 4))
 }

plonky2/src/hash/keccak.rs

@@ -7,16 +7,23 @@ use itertools::Itertools;
 use keccak_hash::keccak;
 
 use crate::hash::hash_types::{BytesHash, RichField};
-use crate::hash::hashing::{PlonkyPermutation, SPONGE_WIDTH};
+use crate::hash::hashing::PlonkyPermutation;
-use crate::plonk::config::Hasher;
+use crate::plonk::config::{Hasher, KeccakHashConfig};
 use crate::util::serialization::Write;
 
+pub const SPONGE_RATE: usize = 8;
+pub const SPONGE_CAPACITY: usize = 4;
+pub const SPONGE_WIDTH: usize = SPONGE_RATE + SPONGE_CAPACITY;
+
 /// Keccak-256 pseudo-permutation (not necessarily one-to-one) used in the challenger.
 /// A state `input: [F; 12]` is sent to the field representation of `H(input) || H(H(input)) || H(H(H(input)))`
 /// where `H` is the Keccak-256 hash.
 pub struct KeccakPermutation;
-impl<F: RichField> PlonkyPermutation<F> for KeccakPermutation {
+impl<F: RichField> PlonkyPermutation<F, KeccakHashConfig> for KeccakPermutation {
-    fn permute(input: [F; SPONGE_WIDTH]) -> [F; SPONGE_WIDTH] {
+    fn permute(input: [F; SPONGE_WIDTH]) -> [F; SPONGE_WIDTH]
+    where
+        [(); SPONGE_WIDTH]:,
+    {
         let mut state = vec![0u8; SPONGE_WIDTH * size_of::<u64>()];
         for i in 0..SPONGE_WIDTH {
             state[i * size_of::<u64>()..(i + 1) * size_of::<u64>()]
@@ -53,8 +60,7 @@ impl<F: RichField> PlonkyPermutation<F> for KeccakPermutation {
 /// Keccak-256 hash function.
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 pub struct KeccakHash<const N: usize>;
-
+impl<F: RichField, const N: usize> Hasher<F, KeccakHashConfig> for KeccakHash<N> {
-impl<F: RichField, const N: usize> Hasher<F> for KeccakHash<N> {
     const HASH_SIZE: usize = N;
     type Hash = BytesHash<N>;
     type Permutation = KeccakPermutation;

plonky2/src/hash/merkle_proofs.rs

@@ -7,7 +7,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::field::extension::Extendable;
 use crate::hash::hash_types::{HashOutTarget, MerkleCapTarget, RichField};
-use crate::hash::hashing::SPONGE_WIDTH;
+use crate::hash::hashing::HashConfig;
 use crate::hash::merkle_tree::MerkleCap;
 use crate::iop::target::{BoolTarget, Target};
 use crate::plonk::circuit_builder::CircuitBuilder;
@@ -16,12 +16,12 @@ use crate::plonk::config::{AlgebraicHasher, Hasher};
 
 #[derive(Clone, Debug, Serialize, Deserialize, Eq, PartialEq)]
 #[serde(bound = "")]
-pub struct MerkleProof<F: RichField, H: Hasher<F>> {
+pub struct MerkleProof<F: RichField, HC: HashConfig, H: Hasher<F, HC>> {
     /// The Merkle digest of each sibling subtree, staying from the bottommost layer.
     pub siblings: Vec<H::Hash>,
 }
 
-impl<F: RichField, H: Hasher<F>> MerkleProof<F, H> {
+impl<F: RichField, HC: HashConfig, H: Hasher<F, HC>> MerkleProof<F, HC, H> {
     pub fn len(&self) -> usize {
         self.siblings.len()
     }
@@ -39,24 +39,30 @@ pub struct MerkleProofTarget {
 
 /// Verifies that the given leaf data is present at the given index in the Merkle tree with the
 /// given root.
-pub fn verify_merkle_proof<F: RichField, H: Hasher<F>>(
+pub fn verify_merkle_proof<F: RichField, HC: HashConfig, H: Hasher<F, HC>>(
     leaf_data: Vec<F>,
     leaf_index: usize,
     merkle_root: H::Hash,
-    proof: &MerkleProof<F, H>,
+    proof: &MerkleProof<F, HC, H>,
-) -> Result<()> {
+) -> Result<()>
+where
+    [(); HC::WIDTH]:,
+{
     let merkle_cap = MerkleCap(vec![merkle_root]);
     verify_merkle_proof_to_cap(leaf_data, leaf_index, &merkle_cap, proof)
 }
 
 /// Verifies that the given leaf data is present at the given index in the Merkle tree with the
 /// given cap.
-pub fn verify_merkle_proof_to_cap<F: RichField, H: Hasher<F>>(
+pub fn verify_merkle_proof_to_cap<F: RichField, HC: HashConfig, H: Hasher<F, HC>>(
     leaf_data: Vec<F>,
     leaf_index: usize,
-    merkle_cap: &MerkleCap<F, H>,
+    merkle_cap: &MerkleCap<F, HC, H>,
-    proof: &MerkleProof<F, H>,
+    proof: &MerkleProof<F, HC, H>,
-) -> Result<()> {
+) -> Result<()>
+where
+    [(); HC::WIDTH]:,
+{
     let mut index = leaf_index;
     let mut current_digest = H::hash_or_noop(&leaf_data);
     for &sibling_digest in proof.siblings.iter() {
@@ -79,28 +85,32 @@ pub fn verify_merkle_proof_to_cap<F: RichField, H: Hasher<F>>(
 impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
     /// Verifies that the given leaf data is present at the given index in the Merkle tree with the
     /// given root. The index is given by its little-endian bits.
-    pub fn verify_merkle_proof<H: AlgebraicHasher<F>>(
+    pub fn verify_merkle_proof<HC: HashConfig, H: AlgebraicHasher<F, HC>>(
         &mut self,
         leaf_data: Vec<Target>,
         leaf_index_bits: &[BoolTarget],
         merkle_root: HashOutTarget,
         proof: &MerkleProofTarget,
-    ) {
+    ) where
+        [(); HC::WIDTH]:,
+    {
         let merkle_cap = MerkleCapTarget(vec![merkle_root]);
-        self.verify_merkle_proof_to_cap::<H>(leaf_data, leaf_index_bits, &merkle_cap, proof);
+        self.verify_merkle_proof_to_cap::<HC, H>(leaf_data, leaf_index_bits, &merkle_cap, proof);
     }
 
     /// Verifies that the given leaf data is present at the given index in the Merkle tree with the
     /// given cap. The index is given by its little-endian bits.
-    pub fn verify_merkle_proof_to_cap<H: AlgebraicHasher<F>>(
+    pub fn verify_merkle_proof_to_cap<HC: HashConfig, H: AlgebraicHasher<F, HC>>(
         &mut self,
         leaf_data: Vec<Target>,
         leaf_index_bits: &[BoolTarget],
         merkle_cap: &MerkleCapTarget,
         proof: &MerkleProofTarget,
-    ) {
+    ) where
+        [(); HC::WIDTH]:,
+    {
         let cap_index = self.le_sum(leaf_index_bits[proof.siblings.len()..].iter().copied());
-        self.verify_merkle_proof_to_cap_with_cap_index::<H>(
+        self.verify_merkle_proof_to_cap_with_cap_index::<HC, H>(
             leaf_data,
             leaf_index_bits,
             cap_index,
@@ -111,22 +121,27 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
 
     /// Same as `verify_merkle_proof_to_cap`, except with the final "cap index" as separate parameter,
     /// rather than being contained in `leaf_index_bits`.
-    pub(crate) fn verify_merkle_proof_to_cap_with_cap_index<H: AlgebraicHasher<F>>(
+    pub(crate) fn verify_merkle_proof_to_cap_with_cap_index<
+        HC: HashConfig,
+        H: AlgebraicHasher<F, HC>,
+    >(
         &mut self,
         leaf_data: Vec<Target>,
         leaf_index_bits: &[BoolTarget],
         cap_index: Target,
         merkle_cap: &MerkleCapTarget,
         proof: &MerkleProofTarget,
-    ) {
+    ) where
+        [(); HC::WIDTH]:,
+    {
         let zero = self.zero();
-        let mut state: HashOutTarget = self.hash_or_noop::<H>(leaf_data);
+        let mut state: HashOutTarget = self.hash_or_noop::<HC, H>(leaf_data);
 
         for (&bit, &sibling) in leaf_index_bits.iter().zip(&proof.siblings) {
-            let mut perm_inputs = [zero; SPONGE_WIDTH];
+            let mut perm_inputs = [zero; HC::WIDTH];
             perm_inputs[..4].copy_from_slice(&state.elements);
             perm_inputs[4..8].copy_from_slice(&sibling.elements);
-            let perm_outs = self.permute_swapped::<H>(perm_inputs, bit);
+            let perm_outs = self.permute_swapped::<HC, H>(perm_inputs, bit);
             let hash_outs = perm_outs[0..4].try_into().unwrap();
             state = HashOutTarget {
                 elements: hash_outs,
@@ -192,7 +207,10 @@ mod tests {
         let n = 1 << log_n;
         let cap_height = 1;
         let leaves = random_data::<F>(n, 7);
-        let tree = MerkleTree::<F, <C as GenericConfig<D>>::Hasher>::new(leaves, cap_height);
+        let tree =
+            MerkleTree::<F, <C as GenericConfig<D>>::HCO, <C as GenericConfig<D>>::Hasher>::new(
+                leaves, cap_height,
+            );
         let i: usize = OsRng.gen_range(0..n);
         let proof = tree.prove(i);
 
@@ -214,7 +232,7 @@ mod tests {
             pw.set_target(data[j], tree.leaves[i][j]);
         }
 
-        builder.verify_merkle_proof_to_cap::<<C as GenericConfig<D>>::InnerHasher>(
+        builder.verify_merkle_proof_to_cap::<<C as GenericConfig<D>>::HCI, <C as GenericConfig<D>>::InnerHasher>(
             data, &i_bits, &cap_t, &proof_t,
         );
 

plonky2/src/hash/merkle_tree.rs

@@ -6,6 +6,7 @@ use plonky2_maybe_rayon::*;
 use serde::{Deserialize, Serialize};
 
 use crate::hash::hash_types::RichField;
+use crate::hash::hashing::HashConfig;
 use crate::hash::merkle_proofs::MerkleProof;
 use crate::plonk::config::{GenericHashOut, Hasher};
 use crate::util::log2_strict;
@@ -15,9 +16,9 @@ use crate::util::log2_strict;
 #[derive(Clone, Debug, Serialize, Deserialize, Eq, PartialEq)]
 #[serde(bound = "")]
 // TODO: Change H to GenericHashOut<F>, since this only cares about the hash, not the hasher.
-pub struct MerkleCap<F: RichField, H: Hasher<F>>(pub Vec<H::Hash>);
+pub struct MerkleCap<F: RichField, HC: HashConfig, H: Hasher<F, HC>>(pub Vec<H::Hash>);
 
-impl<F: RichField, H: Hasher<F>> MerkleCap<F, H> {
+impl<F: RichField, HC: HashConfig, H: Hasher<F, HC>> MerkleCap<F, HC, H> {
     pub fn len(&self) -> usize {
         self.0.len()
     }
@@ -36,7 +37,7 @@ impl<F: RichField, H: Hasher<F>> MerkleCap<F, H> {
 }
 
 #[derive(Clone, Debug)]
-pub struct MerkleTree<F: RichField, H: Hasher<F>> {
+pub struct MerkleTree<F: RichField, HC: HashConfig, H: Hasher<F, HC>> {
     /// The data in the leaves of the Merkle tree.
     pub leaves: Vec<Vec<F>>,
 
@@ -51,7 +52,7 @@ pub struct MerkleTree<F: RichField, H: Hasher<F>> {
     pub digests: Vec<H::Hash>,
 
     /// The Merkle cap.
-    pub cap: MerkleCap<F, H>,
+    pub cap: MerkleCap<F, HC, H>,
 }
 
 fn capacity_up_to_mut<T>(v: &mut Vec<T>, len: usize) -> &mut [MaybeUninit<T>] {
@@ -66,10 +67,13 @@ fn capacity_up_to_mut<T>(v: &mut Vec<T>, len: usize) -> &mut [MaybeUninit<T>] {
     }
 }
 
-fn fill_subtree<F: RichField, H: Hasher<F>>(
+fn fill_subtree<F: RichField, HC: HashConfig, H: Hasher<F, HC>>(
     digests_buf: &mut [MaybeUninit<H::Hash>],
     leaves: &[Vec<F>],
-) -> H::Hash {
+) -> H::Hash
+where
+    [(); HC::WIDTH]:,
+{
     assert_eq!(leaves.len(), digests_buf.len() / 2 + 1);
     if digests_buf.is_empty() {
         H::hash_or_noop(&leaves[0])
@@ -85,8 +89,8 @@ fn fill_subtree<F: RichField, H: Hasher<F>>(
         let (left_leaves, right_leaves) = leaves.split_at(leaves.len() / 2);
 
         let (left_digest, right_digest) = plonky2_maybe_rayon::join(
-            || fill_subtree::<F, H>(left_digests_buf, left_leaves),
+            || fill_subtree::<F, HC, H>(left_digests_buf, left_leaves),
-            || fill_subtree::<F, H>(right_digests_buf, right_leaves),
+            || fill_subtree::<F, HC, H>(right_digests_buf, right_leaves),
         );
 
         left_digest_mem.write(left_digest);
@@ -95,12 +99,14 @@ fn fill_subtree<F: RichField, H: Hasher<F>>(
     }
 }
 
-fn fill_digests_buf<F: RichField, H: Hasher<F>>(
+fn fill_digests_buf<F: RichField, HC: HashConfig, H: Hasher<F, HC>>(
     digests_buf: &mut [MaybeUninit<H::Hash>],
     cap_buf: &mut [MaybeUninit<H::Hash>],
     leaves: &[Vec<F>],
     cap_height: usize,
-) {
+) where
+    [(); HC::WIDTH]:,
+{
     // Special case of a tree that's all cap. The usual case will panic because we'll try to split
     // an empty slice into chunks of `0`. (We would not need this if there was a way to split into
     // `blah` chunks as opposed to chunks _of_ `blah`.)
@@ -126,12 +132,15 @@ fn fill_digests_buf<F: RichField, H: Hasher<F>>(
             // We have `1 << cap_height` sub-trees, one for each entry in `cap`. They are totally
             // independent, so we schedule one task for each. `digests_buf` and `leaves` are split
             // into `1 << cap_height` slices, one for each sub-tree.
-            subtree_cap.write(fill_subtree::<F, H>(subtree_digests, subtree_leaves));
+            subtree_cap.write(fill_subtree::<F, HC, H>(subtree_digests, subtree_leaves));
         },
     );
 }
 
-impl<F: RichField, H: Hasher<F>> MerkleTree<F, H> {
+impl<F: RichField, HC: HashConfig, H: Hasher<F, HC>> MerkleTree<F, HC, H>
+where
+    [(); HC::WIDTH]:,
+{
     pub fn new(leaves: Vec<Vec<F>>, cap_height: usize) -> Self {
         let log2_leaves_len = log2_strict(leaves.len());
         assert!(
@@ -149,7 +158,7 @@ impl<F: RichField, H: Hasher<F>> MerkleTree<F, H> {
 
         let digests_buf = capacity_up_to_mut(&mut digests, num_digests);
         let cap_buf = capacity_up_to_mut(&mut cap, len_cap);
-        fill_digests_buf::<F, H>(digests_buf, cap_buf, &leaves[..], cap_height);
+        fill_digests_buf::<F, HC, H>(digests_buf, cap_buf, &leaves[..], cap_height);
 
         unsafe {
             // SAFETY: `fill_digests_buf` and `cap` initialized the spare capacity up to
@@ -170,7 +179,7 @@ impl<F: RichField, H: Hasher<F>> MerkleTree<F, H> {
     }
 
     /// Create a Merkle proof from a leaf index.
-    pub fn prove(&self, leaf_index: usize) -> MerkleProof<F, H> {
+    pub fn prove(&self, leaf_index: usize) -> MerkleProof<F, HC, H> {
         let cap_height = log2_strict(self.cap.len());
         let num_layers = log2_strict(self.leaves.len()) - cap_height;
         debug_assert_eq!(leaf_index >> (cap_height + num_layers), 0);
@@ -220,15 +229,14 @@ mod tests {
         (0..n).map(|_| F::rand_vec(k)).collect()
     }
 
-    fn verify_all_leaves<
+    fn verify_all_leaves<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>(
-        F: RichField + Extendable<D>,
-        C: GenericConfig<D, F = F>,
-        const D: usize,
-    >(
         leaves: Vec<Vec<F>>,
         cap_height: usize,
-    ) -> Result<()> {
+    ) -> Result<()>
-        let tree = MerkleTree::<F, C::Hasher>::new(leaves.clone(), cap_height);
+    where
+        [(); C::HCO::WIDTH]:,
+    {
+        let tree = MerkleTree::<F, C::HCO, C::Hasher>::new(leaves.clone(), cap_height);
         for (i, leaf) in leaves.into_iter().enumerate() {
             let proof = tree.prove(i);
             verify_merkle_proof_to_cap(leaf, i, &tree.cap, &proof)?;
@@ -247,7 +255,9 @@ mod tests {
         let cap_height = log_n + 1; // Should panic if `cap_height > len_n`.
 
         let leaves = random_data::<F>(1 << log_n, 7);
-        let _ = MerkleTree::<F, <C as GenericConfig<D>>::Hasher>::new(leaves, cap_height);
+        let _ = MerkleTree::<F, <C as GenericConfig<D>>::HCO, <C as GenericConfig<D>>::Hasher>::new(
+            leaves, cap_height,
+        );
     }
 
     #[test]

plonky2/src/hash/path_compression.rs

@@ -5,15 +5,16 @@ use hashbrown::HashMap;
 use num::Integer;
 
 use crate::hash::hash_types::RichField;
+use crate::hash::hashing::HashConfig;
 use crate::hash::merkle_proofs::MerkleProof;
 use crate::plonk::config::Hasher;
 
 /// Compress multiple Merkle proofs on the same tree by removing redundancy in the Merkle paths.
-pub(crate) fn compress_merkle_proofs<F: RichField, H: Hasher<F>>(
+pub(crate) fn compress_merkle_proofs<F: RichField, HC: HashConfig, H: Hasher<F, HC>>(
     cap_height: usize,
     indices: &[usize],
-    proofs: &[MerkleProof<F, H>],
+    proofs: &[MerkleProof<F, HC, H>],
-) -> Vec<MerkleProof<F, H>> {
+) -> Vec<MerkleProof<F, HC, H>> {
     assert!(!proofs.is_empty());
     let height = cap_height + proofs[0].siblings.len();
     let num_leaves = 1 << height;
@@ -53,13 +54,16 @@ pub(crate) fn compress_merkle_proofs<F: RichField, H: Hasher<F>>(
 
 /// Decompress compressed Merkle proofs.
 /// Note: The data and indices must be in the same order as in `compress_merkle_proofs`.
-pub(crate) fn decompress_merkle_proofs<F: RichField, H: Hasher<F>>(
+pub(crate) fn decompress_merkle_proofs<F: RichField, HC: HashConfig, H: Hasher<F, HC>>(
     leaves_data: &[Vec<F>],
     leaves_indices: &[usize],
-    compressed_proofs: &[MerkleProof<F, H>],
+    compressed_proofs: &[MerkleProof<F, HC, H>],
     height: usize,
     cap_height: usize,
-) -> Vec<MerkleProof<F, H>> {
+) -> Vec<MerkleProof<F, HC, H>>
+where
+    [(); HC::WIDTH]:,
+{
     let num_leaves = 1 << height;
     let compressed_proofs = compressed_proofs.to_vec();
     let mut decompressed_proofs = Vec::with_capacity(compressed_proofs.len());
@@ -130,7 +134,11 @@ mod tests {
         let h = 10;
         let cap_height = 3;
         let vs = (0..1 << h).map(|_| vec![F::rand()]).collect::<Vec<_>>();
-        let mt = MerkleTree::<F, <C as GenericConfig<D>>::Hasher>::new(vs.clone(), cap_height);
+        let mt =
+            MerkleTree::<F, <C as GenericConfig<D>>::HCO, <C as GenericConfig<D>>::Hasher>::new(
+                vs.clone(),
+                cap_height,
+            );
 
         let mut rng = OsRng;
         let k = rng.gen_range(1..=1 << h);

plonky2/src/hash/poseidon.rs

@@ -12,11 +12,15 @@ use crate::gates::gate::Gate;
 use crate::gates::poseidon::PoseidonGate;
 use crate::gates::poseidon_mds::PoseidonMdsGate;
 use crate::hash::hash_types::{HashOut, RichField};
-use crate::hash::hashing::{compress, hash_n_to_hash_no_pad, PlonkyPermutation, SPONGE_WIDTH};
+use crate::hash::hashing::{compress, hash_n_to_hash_no_pad, PlonkyPermutation};
 use crate::iop::ext_target::ExtensionTarget;
 use crate::iop::target::{BoolTarget, Target};
 use crate::plonk::circuit_builder::CircuitBuilder;
-use crate::plonk::config::{AlgebraicHasher, Hasher};
+use crate::plonk::config::{AlgebraicHasher, Hasher, PoseidonHashConfig};
+
+pub const SPONGE_RATE: usize = 8;
+pub const SPONGE_CAPACITY: usize = 4;
+pub const SPONGE_WIDTH: usize = SPONGE_RATE + SPONGE_CAPACITY;
 
 // The number of full rounds and partial rounds is given by the
 // calc_round_numbers.py script. They happen to be the same for both
@@ -47,7 +51,7 @@ fn reduce_u160<F: PrimeField64>((n_lo, n_hi): (u128, u32)) -> F {
 }
 
 /// Note that these work for the Goldilocks field, but not necessarily others. See
-/// `generate_constants` about how these were generated. We include enough for a WIDTH of 12;
+/// `generate_constants` about how these were generated. We include enough for a width of 12;
 /// smaller widths just use a subset.
 #[rustfmt::skip]
 pub const ALL_ROUND_CONSTANTS: [u64; MAX_WIDTH * N_ROUNDS]  = [
@@ -150,29 +154,28 @@ pub const ALL_ROUND_CONSTANTS: [u64; MAX_WIDTH * N_ROUNDS]  = [
     0x4543d9df5476d3cb, 0xf172d73e004fc90d, 0xdfd1c4febcc81238, 0xbc8dfb627fe558fc,
 ];
 
-const WIDTH: usize = SPONGE_WIDTH;
 pub trait Poseidon: PrimeField64 {
     // Total number of round constants required: width of the input
     // times number of rounds.
-    const N_ROUND_CONSTANTS: usize = WIDTH * N_ROUNDS;
+    const N_ROUND_CONSTANTS: usize = SPONGE_WIDTH * N_ROUNDS;
 
     // The MDS matrix we use is C + D, where C is the circulant matrix whose first row is given by
     // `MDS_MATRIX_CIRC`, and D is the diagonal matrix whose diagonal is given by `MDS_MATRIX_DIAG`.
-    const MDS_MATRIX_CIRC: [u64; WIDTH];
+    const MDS_MATRIX_CIRC: [u64; SPONGE_WIDTH];
-    const MDS_MATRIX_DIAG: [u64; WIDTH];
+    const MDS_MATRIX_DIAG: [u64; SPONGE_WIDTH];
 
     // Precomputed constants for the fast Poseidon calculation. See
     // the paper.
-    const FAST_PARTIAL_FIRST_ROUND_CONSTANT: [u64; WIDTH];
+    const FAST_PARTIAL_FIRST_ROUND_CONSTANT: [u64; SPONGE_WIDTH];
     const FAST_PARTIAL_ROUND_CONSTANTS: [u64; N_PARTIAL_ROUNDS];
-    const FAST_PARTIAL_ROUND_VS: [[u64; WIDTH - 1]; N_PARTIAL_ROUNDS];
+    const FAST_PARTIAL_ROUND_VS: [[u64; SPONGE_WIDTH - 1]; N_PARTIAL_ROUNDS];
-    const FAST_PARTIAL_ROUND_W_HATS: [[u64; WIDTH - 1]; N_PARTIAL_ROUNDS];
+    const FAST_PARTIAL_ROUND_W_HATS: [[u64; SPONGE_WIDTH - 1]; N_PARTIAL_ROUNDS];
-    const FAST_PARTIAL_ROUND_INITIAL_MATRIX: [[u64; WIDTH - 1]; WIDTH - 1];
+    const FAST_PARTIAL_ROUND_INITIAL_MATRIX: [[u64; SPONGE_WIDTH - 1]; SPONGE_WIDTH - 1];
 
     #[inline(always)]
     #[unroll_for_loops]
-    fn mds_row_shf(r: usize, v: &[u64; WIDTH]) -> u128 {
+    fn mds_row_shf(r: usize, v: &[u64; SPONGE_WIDTH]) -> u128 {
-        debug_assert!(r < WIDTH);
+        debug_assert!(r < SPONGE_WIDTH);
         // The values of `MDS_MATRIX_CIRC` and `MDS_MATRIX_DIAG` are
         // known to be small, so we can accumulate all the products for
         // each row and reduce just once at the end (done by the
@@ -184,8 +187,8 @@ pub trait Poseidon: PrimeField64 {
 
         // This is a hacky way of fully unrolling the loop.
         for i in 0..12 {
-            if i < WIDTH {
+            if i < SPONGE_WIDTH {
-                res += (v[(i + r) % WIDTH] as u128) * (Self::MDS_MATRIX_CIRC[i] as u128);
+                res += (v[(i + r) % SPONGE_WIDTH] as u128) * (Self::MDS_MATRIX_CIRC[i] as u128);
             }
         }
         res += (v[r] as u128) * (Self::MDS_MATRIX_DIAG[r] as u128);
@@ -196,13 +199,13 @@ pub trait Poseidon: PrimeField64 {
     /// Same as `mds_row_shf` for field extensions of `Self`.
     fn mds_row_shf_field<F: FieldExtension<D, BaseField = Self>, const D: usize>(
         r: usize,
-        v: &[F; WIDTH],
+        v: &[F; SPONGE_WIDTH],
     ) -> F {
-        debug_assert!(r < WIDTH);
+        debug_assert!(r < SPONGE_WIDTH);
         let mut res = F::ZERO;
 
-        for i in 0..WIDTH {
+        for i in 0..SPONGE_WIDTH {
-            res += v[(i + r) % WIDTH] * F::from_canonical_u64(Self::MDS_MATRIX_CIRC[i]);
+            res += v[(i + r) % SPONGE_WIDTH] * F::from_canonical_u64(Self::MDS_MATRIX_CIRC[i]);
         }
         res += v[r] * F::from_canonical_u64(Self::MDS_MATRIX_DIAG[r]);
 
@@ -213,17 +216,17 @@ pub trait Poseidon: PrimeField64 {
     fn mds_row_shf_circuit<const D: usize>(
         builder: &mut CircuitBuilder<Self, D>,
         r: usize,
-        v: &[ExtensionTarget<D>; WIDTH],
+        v: &[ExtensionTarget<D>; SPONGE_WIDTH],
     ) -> ExtensionTarget<D>
     where
         Self: RichField + Extendable<D>,
     {
-        debug_assert!(r < WIDTH);
+        debug_assert!(r < SPONGE_WIDTH);
         let mut res = builder.zero_extension();
 
-        for i in 0..WIDTH {
+        for i in 0..SPONGE_WIDTH {
             let c = Self::from_canonical_u64(<Self as Poseidon>::MDS_MATRIX_CIRC[i]);
-            res = builder.mul_const_add_extension(c, v[(i + r) % WIDTH], res);
+            res = builder.mul_const_add_extension(c, v[(i + r) % SPONGE_WIDTH], res);
         }
         {
             let c = Self::from_canonical_u64(<Self as Poseidon>::MDS_MATRIX_DIAG[r]);
@@ -235,17 +238,17 @@ pub trait Poseidon: PrimeField64 {
 
     #[inline(always)]
     #[unroll_for_loops]
-    fn mds_layer(state_: &[Self; WIDTH]) -> [Self; WIDTH] {
+    fn mds_layer(state_: &[Self; SPONGE_WIDTH]) -> [Self; SPONGE_WIDTH] {
-        let mut result = [Self::ZERO; WIDTH];
+        let mut result = [Self::ZERO; SPONGE_WIDTH];
 
-        let mut state = [0u64; WIDTH];
+        let mut state = [0u64; SPONGE_WIDTH];
-        for r in 0..WIDTH {
+        for r in 0..SPONGE_WIDTH {
             state[r] = state_[r].to_noncanonical_u64();
         }
 
         // This is a hacky way of fully unrolling the loop.
         for r in 0..12 {
-            if r < WIDTH {
+            if r < SPONGE_WIDTH {
                 let sum = Self::mds_row_shf(r, &state);
                 let sum_lo = sum as u64;
                 let sum_hi = (sum >> 64) as u32;
@@ -258,11 +261,11 @@ pub trait Poseidon: PrimeField64 {
 
     /// Same as `mds_layer` for field extensions of `Self`.
     fn mds_layer_field<F: FieldExtension<D, BaseField = Self>, const D: usize>(
-        state: &[F; WIDTH],
+        state: &[F; SPONGE_WIDTH],
-    ) -> [F; WIDTH] {
+    ) -> [F; SPONGE_WIDTH] {
-        let mut result = [F::ZERO; WIDTH];
+        let mut result = [F::ZERO; SPONGE_WIDTH];
 
-        for r in 0..WIDTH {
+        for r in 0..SPONGE_WIDTH {
             result[r] = Self::mds_row_shf_field(r, state);
         }
 
@@ -272,8 +275,8 @@ pub trait Poseidon: PrimeField64 {
     /// Recursive version of `mds_layer`.
     fn mds_layer_circuit<const D: usize>(
         builder: &mut CircuitBuilder<Self, D>,
-        state: &[ExtensionTarget<D>; WIDTH],
+        state: &[ExtensionTarget<D>; SPONGE_WIDTH],
-    ) -> [ExtensionTarget<D>; WIDTH]
+    ) -> [ExtensionTarget<D>; SPONGE_WIDTH]
     where
         Self: RichField + Extendable<D>,
     {
@@ -281,11 +284,11 @@ pub trait Poseidon: PrimeField64 {
         let mds_gate = PoseidonMdsGate::<Self, D>::new();
         if builder.config.num_routed_wires >= mds_gate.num_wires() {
             let index = builder.add_gate(mds_gate, vec![]);
-            for i in 0..WIDTH {
+            for i in 0..SPONGE_WIDTH {
                 let input_wire = PoseidonMdsGate::<Self, D>::wires_input(i);
                 builder.connect_extension(state[i], ExtensionTarget::from_range(index, input_wire));
             }
-            (0..WIDTH)
+            (0..SPONGE_WIDTH)
                 .map(|i| {
                     let output_wire = PoseidonMdsGate::<Self, D>::wires_output(i);
                     ExtensionTarget::from_range(index, output_wire)
@@ -294,9 +297,9 @@ pub trait Poseidon: PrimeField64 {
                 .try_into()
                 .unwrap()
         } else {
-            let mut result = [builder.zero_extension(); WIDTH];
+            let mut result = [builder.zero_extension(); SPONGE_WIDTH];
 
-            for r in 0..WIDTH {
+            for r in 0..SPONGE_WIDTH {
                 result[r] = Self::mds_row_shf_circuit(builder, r, state);
             }
 
@@ -307,10 +310,10 @@ pub trait Poseidon: PrimeField64 {
     #[inline(always)]
     #[unroll_for_loops]
     fn partial_first_constant_layer<F: FieldExtension<D, BaseField = Self>, const D: usize>(
-        state: &mut [F; WIDTH],
+        state: &mut [F; SPONGE_WIDTH],
     ) {
         for i in 0..12 {
-            if i < WIDTH {
+            if i < SPONGE_WIDTH {
                 state[i] += F::from_canonical_u64(Self::FAST_PARTIAL_FIRST_ROUND_CONSTANT[i]);
             }
         }
@@ -319,11 +322,11 @@ pub trait Poseidon: PrimeField64 {
     /// Recursive version of `partial_first_constant_layer`.
     fn partial_first_constant_layer_circuit<const D: usize>(
         builder: &mut CircuitBuilder<Self, D>,
-        state: &mut [ExtensionTarget<D>; WIDTH],
+        state: &mut [ExtensionTarget<D>; SPONGE_WIDTH],
     ) where
         Self: RichField + Extendable<D>,
     {
-        for i in 0..WIDTH {
+        for i in 0..SPONGE_WIDTH {
             let c = <Self as Poseidon>::FAST_PARTIAL_FIRST_ROUND_CONSTANT[i];
             let c = Self::Extension::from_canonical_u64(c);
             let c = builder.constant_extension(c);
@@ -334,9 +337,9 @@ pub trait Poseidon: PrimeField64 {
     #[inline(always)]
     #[unroll_for_loops]
     fn mds_partial_layer_init<F: FieldExtension<D, BaseField = Self>, const D: usize>(
-        state: &[F; WIDTH],
+        state: &[F; SPONGE_WIDTH],
-    ) -> [F; WIDTH] {
+    ) -> [F; SPONGE_WIDTH] {
-        let mut result = [F::ZERO; WIDTH];
+        let mut result = [F::ZERO; SPONGE_WIDTH];
 
         // Initial matrix has first row/column = [1, 0, ..., 0];
 
@@ -344,9 +347,9 @@ pub trait Poseidon: PrimeField64 {
         result[0] = state[0];
 
         for r in 1..12 {
-            if r < WIDTH {
+            if r < SPONGE_WIDTH {
                 for c in 1..12 {
-                    if c < WIDTH {
+                    if c < SPONGE_WIDTH {
                         // NB: FAST_PARTIAL_ROUND_INITIAL_MATRIX is stored in
                         // row-major order so that this dot product is cache
                         // friendly.
@@ -364,17 +367,17 @@ pub trait Poseidon: PrimeField64 {
     /// Recursive version of `mds_partial_layer_init`.
     fn mds_partial_layer_init_circuit<const D: usize>(
         builder: &mut CircuitBuilder<Self, D>,
-        state: &[ExtensionTarget<D>; WIDTH],
+        state: &[ExtensionTarget<D>; SPONGE_WIDTH],
-    ) -> [ExtensionTarget<D>; WIDTH]
+    ) -> [ExtensionTarget<D>; SPONGE_WIDTH]
     where
         Self: RichField + Extendable<D>,
     {
-        let mut result = [builder.zero_extension(); WIDTH];
+        let mut result = [builder.zero_extension(); SPONGE_WIDTH];
 
         result[0] = state[0];
 
-        for r in 1..WIDTH {
+        for r in 1..SPONGE_WIDTH {
-            for c in 1..WIDTH {
+            for c in 1..SPONGE_WIDTH {
                 let t = <Self as Poseidon>::FAST_PARTIAL_ROUND_INITIAL_MATRIX[r - 1][c - 1];
                 let t = Self::Extension::from_canonical_u64(t);
                 let t = builder.constant_extension(t);
@@ -394,12 +397,12 @@ pub trait Poseidon: PrimeField64 {
     /// (t-1)x(t-1) identity matrix.
     #[inline(always)]
     #[unroll_for_loops]
-    fn mds_partial_layer_fast(state: &[Self; WIDTH], r: usize) -> [Self; WIDTH] {
+    fn mds_partial_layer_fast(state: &[Self; SPONGE_WIDTH], r: usize) -> [Self; SPONGE_WIDTH] {
         // Set d = [M_00 | w^] dot [state]
 
         let mut d_sum = (0u128, 0u32); // u160 accumulator
         for i in 1..12 {
-            if i < WIDTH {
+            if i < SPONGE_WIDTH {
                 let t = Self::FAST_PARTIAL_ROUND_W_HATS[r][i - 1] as u128;
                 let si = state[i].to_noncanonical_u64() as u128;
                 d_sum = add_u160_u128(d_sum, si * t);
@@ -411,10 +414,10 @@ pub trait Poseidon: PrimeField64 {
         let d = reduce_u160::<Self>(d_sum);
 
         // result = [d] concat [state[0] * v + state[shift up by 1]]
-        let mut result = [Self::ZERO; WIDTH];
+        let mut result = [Self::ZERO; SPONGE_WIDTH];
         result[0] = d;
         for i in 1..12 {
-            if i < WIDTH {
+            if i < SPONGE_WIDTH {
                 let t = Self::from_canonical_u64(Self::FAST_PARTIAL_ROUND_VS[r][i - 1]);
                 result[i] = state[i].multiply_accumulate(state[0], t);
             }
@@ -424,21 +427,21 @@ pub trait Poseidon: PrimeField64 {
 
     /// Same as `mds_partial_layer_fast` for field extensions of `Self`.
     fn mds_partial_layer_fast_field<F: FieldExtension<D, BaseField = Self>, const D: usize>(
-        state: &[F; WIDTH],
+        state: &[F; SPONGE_WIDTH],
         r: usize,
-    ) -> [F; WIDTH] {
+    ) -> [F; SPONGE_WIDTH] {
         let s0 = state[0];
         let mds0to0 = Self::MDS_MATRIX_CIRC[0] + Self::MDS_MATRIX_DIAG[0];
         let mut d = s0 * F::from_canonical_u64(mds0to0);
-        for i in 1..WIDTH {
+        for i in 1..SPONGE_WIDTH {
             let t = F::from_canonical_u64(Self::FAST_PARTIAL_ROUND_W_HATS[r][i - 1]);
             d += state[i] * t;
         }
 
         // result = [d] concat [state[0] * v + state[shift up by 1]]
-        let mut result = [F::ZERO; WIDTH];
+        let mut result = [F::ZERO; SPONGE_WIDTH];
         result[0] = d;
-        for i in 1..WIDTH {
+        for i in 1..SPONGE_WIDTH {
             let t = F::from_canonical_u64(Self::FAST_PARTIAL_ROUND_VS[r][i - 1]);
             result[i] = state[0] * t + state[i];
         }
@@ -448,25 +451,25 @@ pub trait Poseidon: PrimeField64 {
     /// Recursive version of `mds_partial_layer_fast`.
     fn mds_partial_layer_fast_circuit<const D: usize>(
         builder: &mut CircuitBuilder<Self, D>,
-        state: &[ExtensionTarget<D>; WIDTH],
+        state: &[ExtensionTarget<D>; SPONGE_WIDTH],
         r: usize,
-    ) -> [ExtensionTarget<D>; WIDTH]
+    ) -> [ExtensionTarget<D>; SPONGE_WIDTH]
     where
         Self: RichField + Extendable<D>,
     {
         let s0 = state[0];
         let mds0to0 = Self::MDS_MATRIX_CIRC[0] + Self::MDS_MATRIX_DIAG[0];
         let mut d = builder.mul_const_extension(Self::from_canonical_u64(mds0to0), s0);
-        for i in 1..WIDTH {
+        for i in 1..SPONGE_WIDTH {
             let t = <Self as Poseidon>::FAST_PARTIAL_ROUND_W_HATS[r][i - 1];
             let t = Self::Extension::from_canonical_u64(t);
             let t = builder.constant_extension(t);
             d = builder.mul_add_extension(t, state[i], d);
         }
 
-        let mut result = [builder.zero_extension(); WIDTH];
+        let mut result = [builder.zero_extension(); SPONGE_WIDTH];
         result[0] = d;
-        for i in 1..WIDTH {
+        for i in 1..SPONGE_WIDTH {
             let t = <Self as Poseidon>::FAST_PARTIAL_ROUND_VS[r][i - 1];
             let t = Self::Extension::from_canonical_u64(t);
             let t = builder.constant_extension(t);
@@ -477,10 +480,10 @@ pub trait Poseidon: PrimeField64 {
 
     #[inline(always)]
     #[unroll_for_loops]
-    fn constant_layer(state: &mut [Self; WIDTH], round_ctr: usize) {
+    fn constant_layer(state: &mut [Self; SPONGE_WIDTH], round_ctr: usize) {
         for i in 0..12 {
-            if i < WIDTH {
+            if i < SPONGE_WIDTH {
-                let round_constant = ALL_ROUND_CONSTANTS[i + WIDTH * round_ctr];
+                let round_constant = ALL_ROUND_CONSTANTS[i + SPONGE_WIDTH * round_ctr];
                 unsafe {
                     state[i] = state[i].add_canonical_u64(round_constant);
                 }
@@ -490,24 +493,24 @@ pub trait Poseidon: PrimeField64 {
 
     /// Same as `constant_layer` for field extensions of `Self`.
     fn constant_layer_field<F: FieldExtension<D, BaseField = Self>, const D: usize>(
-        state: &mut [F; WIDTH],
+        state: &mut [F; SPONGE_WIDTH],
         round_ctr: usize,
     ) {
-        for i in 0..WIDTH {
+        for i in 0..SPONGE_WIDTH {
-            state[i] += F::from_canonical_u64(ALL_ROUND_CONSTANTS[i + WIDTH * round_ctr]);
+            state[i] += F::from_canonical_u64(ALL_ROUND_CONSTANTS[i + SPONGE_WIDTH * round_ctr]);
         }
     }
 
     /// Recursive version of `constant_layer`.
     fn constant_layer_circuit<const D: usize>(
         builder: &mut CircuitBuilder<Self, D>,
-        state: &mut [ExtensionTarget<D>; WIDTH],
+        state: &mut [ExtensionTarget<D>; SPONGE_WIDTH],
         round_ctr: usize,
     ) where
         Self: RichField + Extendable<D>,
     {
-        for i in 0..WIDTH {
+        for i in 0..SPONGE_WIDTH {
-            let c = ALL_ROUND_CONSTANTS[i + WIDTH * round_ctr];
+            let c = ALL_ROUND_CONSTANTS[i + SPONGE_WIDTH * round_ctr];
             let c = Self::Extension::from_canonical_u64(c);
             let c = builder.constant_extension(c);
             state[i] = builder.add_extension(state[i], c);
@@ -537,9 +540,9 @@ pub trait Poseidon: PrimeField64 {
 
     #[inline(always)]
     #[unroll_for_loops]
-    fn sbox_layer(state: &mut [Self; WIDTH]) {
+    fn sbox_layer(state: &mut [Self; SPONGE_WIDTH]) {
         for i in 0..12 {
-            if i < WIDTH {
+            if i < SPONGE_WIDTH {
                 state[i] = Self::sbox_monomial(state[i]);
             }
         }
@@ -547,9 +550,9 @@ pub trait Poseidon: PrimeField64 {
 
     /// Same as `sbox_layer` for field extensions of `Self`.
     fn sbox_layer_field<F: FieldExtension<D, BaseField = Self>, const D: usize>(
-        state: &mut [F; WIDTH],
+        state: &mut [F; SPONGE_WIDTH],
     ) {
-        for i in 0..WIDTH {
+        for i in 0..SPONGE_WIDTH {
             state[i] = Self::sbox_monomial(state[i]);
         }
     }
@@ -557,17 +560,17 @@ pub trait Poseidon: PrimeField64 {
     /// Recursive version of `sbox_layer`.
     fn sbox_layer_circuit<const D: usize>(
         builder: &mut CircuitBuilder<Self, D>,
-        state: &mut [ExtensionTarget<D>; WIDTH],
+        state: &mut [ExtensionTarget<D>; SPONGE_WIDTH],
     ) where
         Self: RichField + Extendable<D>,
     {
-        for i in 0..WIDTH {
+        for i in 0..SPONGE_WIDTH {
             state[i] = <Self as Poseidon>::sbox_monomial_circuit(builder, state[i]);
         }
     }
 
     #[inline]
-    fn full_rounds(state: &mut [Self; WIDTH], round_ctr: &mut usize) {
+    fn full_rounds(state: &mut [Self; SPONGE_WIDTH], round_ctr: &mut usize) {
         for _ in 0..HALF_N_FULL_ROUNDS {
             Self::constant_layer(state, *round_ctr);
             Self::sbox_layer(state);
@@ -577,7 +580,7 @@ pub trait Poseidon: PrimeField64 {
     }
 
     #[inline]
-    fn partial_rounds(state: &mut [Self; WIDTH], round_ctr: &mut usize) {
+    fn partial_rounds(state: &mut [Self; SPONGE_WIDTH], round_ctr: &mut usize) {
         Self::partial_first_constant_layer(state);
         *state = Self::mds_partial_layer_init(state);
 
@@ -592,7 +595,7 @@ pub trait Poseidon: PrimeField64 {
     }
 
     #[inline]
-    fn poseidon(input: [Self; WIDTH]) -> [Self; WIDTH] {
+    fn poseidon(input: [Self; SPONGE_WIDTH]) -> [Self; SPONGE_WIDTH] {
         let mut state = input;
         let mut round_ctr = 0;
 
@@ -606,7 +609,7 @@ pub trait Poseidon: PrimeField64 {
 
     // For testing only, to ensure that various tricks are correct.
     #[inline]
-    fn partial_rounds_naive(state: &mut [Self; WIDTH], round_ctr: &mut usize) {
+    fn partial_rounds_naive(state: &mut [Self; SPONGE_WIDTH], round_ctr: &mut usize) {
         for _ in 0..N_PARTIAL_ROUNDS {
             Self::constant_layer(state, *round_ctr);
             state[0] = Self::sbox_monomial(state[0]);
@@ -616,7 +619,7 @@ pub trait Poseidon: PrimeField64 {
     }
 
     #[inline]
-    fn poseidon_naive(input: [Self; WIDTH]) -> [Self; WIDTH] {
+    fn poseidon_naive(input: [Self; SPONGE_WIDTH]) -> [Self; SPONGE_WIDTH] {
         let mut state = input;
         let mut round_ctr = 0;
 
@@ -630,7 +633,7 @@ pub trait Poseidon: PrimeField64 {
 }
 
 pub struct PoseidonPermutation;
-impl<F: RichField> PlonkyPermutation<F> for PoseidonPermutation {
+impl<F: RichField> PlonkyPermutation<F, PoseidonHashConfig> for PoseidonPermutation {
     fn permute(input: [F; SPONGE_WIDTH]) -> [F; SPONGE_WIDTH] {
         F::poseidon(input)
     }
@@ -639,21 +642,21 @@ impl<F: RichField> PlonkyPermutation<F> for PoseidonPermutation {
 /// Poseidon hash function.
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 pub struct PoseidonHash;
-impl<F: RichField> Hasher<F> for PoseidonHash {
+impl<F: RichField> Hasher<F, PoseidonHashConfig> for PoseidonHash {
     const HASH_SIZE: usize = 4 * 8;
     type Hash = HashOut<F>;
     type Permutation = PoseidonPermutation;
 
     fn hash_no_pad(input: &[F]) -> Self::Hash {
-        hash_n_to_hash_no_pad::<F, Self::Permutation>(input)
+        hash_n_to_hash_no_pad::<F, PoseidonHashConfig, Self::Permutation>(input)
     }
 
     fn two_to_one(left: Self::Hash, right: Self::Hash) -> Self::Hash {
-        compress::<F, Self::Permutation>(left, right)
+        compress::<F, PoseidonHashConfig, Self::Permutation>(left, right)
     }
 }
 
-impl<F: RichField> AlgebraicHasher<F> for PoseidonHash {
+impl<F: RichField> AlgebraicHasher<F, PoseidonHashConfig> for PoseidonHash {
     fn permute_swapped<const D: usize>(
         inputs: [Target; SPONGE_WIDTH],
         swap: BoolTarget,
@@ -688,8 +691,7 @@ impl<F: RichField> AlgebraicHasher<F> for PoseidonHash {
 #[cfg(test)]
 pub(crate) mod test_helpers {
     use crate::field::types::Field;
-    use crate::hash::hashing::SPONGE_WIDTH;
+    use crate::hash::poseidon::{Poseidon, SPONGE_WIDTH};
-    use crate::hash::poseidon::Poseidon;
 
     pub(crate) fn check_test_vectors<F: Field>(
         test_vectors: Vec<([u64; SPONGE_WIDTH], [u64; SPONGE_WIDTH])>,

plonky2/src/iop/challenger.rs

@@ -4,7 +4,7 @@ use core::marker::PhantomData;
 
 use crate::field::extension::{Extendable, FieldExtension};
 use crate::hash::hash_types::{HashOut, HashOutTarget, MerkleCapTarget, RichField};
-use crate::hash::hashing::{PlonkyPermutation, SPONGE_RATE, SPONGE_WIDTH};
+use crate::hash::hashing::{HashConfig, PlonkyPermutation};
 use crate::hash::merkle_tree::MerkleCap;
 use crate::iop::ext_target::ExtensionTarget;
 use crate::iop::target::Target;
@@ -13,8 +13,11 @@ use crate::plonk::config::{AlgebraicHasher, GenericHashOut, Hasher};
 
 /// Observes prover messages, and generates challenges by hashing the transcript, a la Fiat-Shamir.
 #[derive(Clone)]
-pub struct Challenger<F: RichField, H: Hasher<F>> {
+pub struct Challenger<F: RichField, HC: HashConfig, H: Hasher<F, HC>>
-    pub(crate) sponge_state: [F; SPONGE_WIDTH],
+where
+    [(); HC::WIDTH]:,
+{
+    pub(crate) sponge_state: [F; HC::WIDTH],
     pub(crate) input_buffer: Vec<F>,
     output_buffer: Vec<F>,
     _phantom: PhantomData<H>,
@@ -28,23 +31,32 @@ pub struct Challenger<F: RichField, H: Hasher<F>> {
 /// design, but it can be viewed as a duplex sponge whose inputs are sometimes zero (when we perform
 /// multiple squeezes) and whose outputs are sometimes ignored (when we perform multiple
 /// absorptions). Thus the security properties of a duplex sponge still apply to our design.
-impl<F: RichField, H: Hasher<F>> Challenger<F, H> {
+impl<F: RichField, HC: HashConfig, H: Hasher<F, HC>> Challenger<F, HC, H>
-    pub fn new() -> Challenger<F, H> {
+where
+    [(); HC::WIDTH]:,
+{
+    pub fn new() -> Challenger<F, HC, H>
+    where
+        [(); HC::WIDTH]:,
+    {
         Challenger {
-            sponge_state: [F::ZERO; SPONGE_WIDTH],
+            sponge_state: [F::ZERO; HC::WIDTH],
-            input_buffer: Vec::with_capacity(SPONGE_RATE),
+            input_buffer: Vec::with_capacity(HC::RATE),
-            output_buffer: Vec::with_capacity(SPONGE_RATE),
+            output_buffer: Vec::with_capacity(HC::RATE),
             _phantom: Default::default(),
         }
     }
 
-    pub fn observe_element(&mut self, element: F) {
+    pub fn observe_element(&mut self, element: F)
+    where
+        [(); HC::WIDTH]:,
+    {
         // Any buffered outputs are now invalid, since they wouldn't reflect this input.
         self.output_buffer.clear();
 
         self.input_buffer.push(element);
 
-        if self.input_buffer.len() == SPONGE_RATE {
+        if self.input_buffer.len() == HC::RATE {
             self.duplexing();
         }
     }
@@ -52,11 +64,15 @@ impl<F: RichField, H: Hasher<F>> Challenger<F, H> {
     pub fn observe_extension_element<const D: usize>(&mut self, element: &F::Extension)
     where
         F: RichField + Extendable<D>,
+        [(); HC::WIDTH]:,
     {
         self.observe_elements(&element.to_basefield_array());
     }
 
-    pub fn observe_elements(&mut self, elements: &[F]) {
+    pub fn observe_elements(&mut self, elements: &[F])
+    where
+        [(); HC::WIDTH]:,
+    {
         for &element in elements {
             self.observe_element(element);
         }
@@ -65,23 +81,33 @@ impl<F: RichField, H: Hasher<F>> Challenger<F, H> {
     pub fn observe_extension_elements<const D: usize>(&mut self, elements: &[F::Extension])
     where
         F: RichField + Extendable<D>,
+        [(); HC::WIDTH]:,
     {
         for element in elements {
             self.observe_extension_element(element);
         }
     }
 
-    pub fn observe_hash<OH: Hasher<F>>(&mut self, hash: OH::Hash) {
+    pub fn observe_hash<OHC: HashConfig, OH: Hasher<F, OHC>>(&mut self, hash: OH::Hash)
+    where
+        [(); OHC::WIDTH]:,
+    {
         self.observe_elements(&hash.to_vec())
     }
 
-    pub fn observe_cap<OH: Hasher<F>>(&mut self, cap: &MerkleCap<F, OH>) {
+    pub fn observe_cap<OHC: HashConfig, OH: Hasher<F, OHC>>(&mut self, cap: &MerkleCap<F, OHC, OH>)
+    where
+        [(); OHC::WIDTH]:,
+    {
         for &hash in &cap.0 {
-            self.observe_hash::<OH>(hash);
+            self.observe_hash::<OHC, OH>(hash);
         }
     }
 
-    pub fn get_challenge(&mut self) -> F {
+    pub fn get_challenge(&mut self) -> F
+    where
+        [(); HC::WIDTH]:,
+    {
         // If we have buffered inputs, we must perform a duplexing so that the challenge will
         // reflect them. Or if we've run out of outputs, we must perform a duplexing to get more.
         if !self.input_buffer.is_empty() || self.output_buffer.is_empty() {
@@ -93,11 +119,17 @@ impl<F: RichField, H: Hasher<F>> Challenger<F, H> {
             .expect("Output buffer should be non-empty")
     }
 
-    pub fn get_n_challenges(&mut self, n: usize) -> Vec<F> {
+    pub fn get_n_challenges(&mut self, n: usize) -> Vec<F>
+    where
+        [(); HC::WIDTH]:,
+    {
         (0..n).map(|_| self.get_challenge()).collect()
     }
 
-    pub fn get_hash(&mut self) -> HashOut<F> {
+    pub fn get_hash(&mut self) -> HashOut<F>
+    where
+        [(); HC::WIDTH]:,
+    {
         HashOut {
             elements: [
                 self.get_challenge(),
@@ -111,6 +143,7 @@ impl<F: RichField, H: Hasher<F>> Challenger<F, H> {
     pub fn get_extension_challenge<const D: usize>(&mut self) -> F::Extension
     where
         F: RichField + Extendable<D>,
+        [(); HC::WIDTH]:,
     {
         let mut arr = [F::ZERO; D];
         arr.copy_from_slice(&self.get_n_challenges(D));
@@ -120,6 +153,7 @@ impl<F: RichField, H: Hasher<F>> Challenger<F, H> {
     pub fn get_n_extension_challenges<const D: usize>(&mut self, n: usize) -> Vec<F::Extension>
     where
         F: RichField + Extendable<D>,
+        [(); HC::WIDTH]:,
     {
         (0..n)
             .map(|_| self.get_extension_challenge::<D>())
@@ -128,8 +162,11 @@ impl<F: RichField, H: Hasher<F>> Challenger<F, H> {
 
     /// Absorb any buffered inputs. After calling this, the input buffer will be empty, and the
     /// output buffer will be full.
-    fn duplexing(&mut self) {
+    fn duplexing(&mut self)
-        assert!(self.input_buffer.len() <= SPONGE_RATE);
+    where
+        [(); HC::WIDTH]:,
+    {
+        assert!(self.input_buffer.len() <= HC::RATE);
 
         // Overwrite the first r elements with the inputs. This differs from a standard sponge,
         // where we would xor or add in the inputs. This is a well-known variant, though,
@@ -143,10 +180,10 @@ impl<F: RichField, H: Hasher<F>> Challenger<F, H> {
 
         self.output_buffer.clear();
         self.output_buffer
-            .extend_from_slice(&self.sponge_state[0..SPONGE_RATE]);
+            .extend_from_slice(&self.sponge_state[0..HC::RATE]);
     }
 
-    pub fn compact(&mut self) -> [F; SPONGE_WIDTH] {
+    pub fn compact(&mut self) -> [F; HC::WIDTH] {
         if !self.input_buffer.is_empty() {
             self.duplexing();
         }
@@ -155,37 +192,54 @@ impl<F: RichField, H: Hasher<F>> Challenger<F, H> {
     }
 }
 
-impl<F: RichField, H: AlgebraicHasher<F>> Default for Challenger<F, H> {
+impl<F: RichField, HC: HashConfig, H: AlgebraicHasher<F, HC>> Default for Challenger<F, HC, H>
-    fn default() -> Self {
+where
+    [(); HC::WIDTH]:,
+{
+    fn default() -> Self
+    where
+        [(); HC::WIDTH]:,
+    {
         Self::new()
     }
 }
 
 /// A recursive version of `Challenger`. The main difference is that `RecursiveChallenger`'s input
-/// buffer can grow beyond `SPONGE_RATE`. This is so that `observe_element` etc do not need access
+/// buffer can grow beyond `HC::RATE`. This is so that `observe_element` etc do not need access
 /// to the `CircuitBuilder`.
-pub struct RecursiveChallenger<F: RichField + Extendable<D>, H: AlgebraicHasher<F>, const D: usize>
+pub struct RecursiveChallenger<
+    F: RichField + Extendable<D>,
+    HC: HashConfig,
+    H: AlgebraicHasher<F, HC>,
+    const D: usize,
+> where
+    [(); HC::WIDTH]:,
 {
-    sponge_state: [Target; SPONGE_WIDTH],
+    sponge_state: [Target; HC::WIDTH],
     input_buffer: Vec<Target>,
     output_buffer: Vec<Target>,
     __: PhantomData<(F, H)>,
 }
 
-impl<F: RichField + Extendable<D>, H: AlgebraicHasher<F>, const D: usize>
+impl<F: RichField + Extendable<D>, HC: HashConfig, H: AlgebraicHasher<F, HC>, const D: usize>
-    RecursiveChallenger<F, H, D>
+    RecursiveChallenger<F, HC, H, D>
+where
+    [(); HC::WIDTH]:,
 {
-    pub fn new(builder: &mut CircuitBuilder<F, D>) -> Self {
+    pub fn new(builder: &mut CircuitBuilder<F, D>) -> Self
+    where
+        [(); HC::WIDTH]:,
+    {
         let zero = builder.zero();
         Self {
-            sponge_state: [zero; SPONGE_WIDTH],
+            sponge_state: [zero; HC::WIDTH],
             input_buffer: Vec::new(),
             output_buffer: Vec::new(),
             __: PhantomData,
         }
     }
 
-    pub fn from_state(sponge_state: [Target; SPONGE_WIDTH]) -> Self {
+    pub fn from_state(sponge_state: [Target; HC::WIDTH]) -> Self {
         Self {
             sponge_state,
             input_buffer: vec![],
@@ -194,46 +248,67 @@ impl<F: RichField + Extendable<D>, H: AlgebraicHasher<F>, const D: usize>
         }
     }
 
-    pub(crate) fn observe_element(&mut self, target: Target) {
+    pub(crate) fn observe_element(&mut self, target: Target)
+    where
+        [(); HC::WIDTH]:,
+    {
         // Any buffered outputs are now invalid, since they wouldn't reflect this input.
         self.output_buffer.clear();
 
         self.input_buffer.push(target);
     }
 
-    pub fn observe_elements(&mut self, targets: &[Target]) {
+    pub fn observe_elements(&mut self, targets: &[Target])
+    where
+        [(); HC::WIDTH]:,
+    {
         for &target in targets {
             self.observe_element(target);
         }
     }
 
-    pub fn observe_hash(&mut self, hash: &HashOutTarget) {
+    pub fn observe_hash(&mut self, hash: &HashOutTarget)
+    where
+        [(); HC::WIDTH]:,
+    {
         self.observe_elements(&hash.elements)
     }
 
-    pub fn observe_cap(&mut self, cap: &MerkleCapTarget) {
+    pub fn observe_cap(&mut self, cap: &MerkleCapTarget)
+    where
+        [(); HC::WIDTH]:,
+    {
         for hash in &cap.0 {
             self.observe_hash(hash)
         }
     }
 
-    pub fn observe_extension_element(&mut self, element: ExtensionTarget<D>) {
+    pub fn observe_extension_element(&mut self, element: ExtensionTarget<D>)
+    where
+        [(); HC::WIDTH]:,
+    {
         self.observe_elements(&element.0);
     }
 
-    pub fn observe_extension_elements(&mut self, elements: &[ExtensionTarget<D>]) {
+    pub fn observe_extension_elements(&mut self, elements: &[ExtensionTarget<D>])
+    where
+        [(); HC::WIDTH]:,
+    {
         for &element in elements {
             self.observe_extension_element(element);
         }
     }
 
-    pub fn get_challenge(&mut self, builder: &mut CircuitBuilder<F, D>) -> Target {
+    pub fn get_challenge(&mut self, builder: &mut CircuitBuilder<F, D>) -> Target
+    where
+        [(); HC::WIDTH]:,
+    {
         self.absorb_buffered_inputs(builder);
 
         if self.output_buffer.is_empty() {
             // Evaluate the permutation to produce `r` new outputs.
-            self.sponge_state = builder.permute::<H>(self.sponge_state);
+            self.sponge_state = builder.permute::<HC, H>(self.sponge_state);
-            self.output_buffer = self.sponge_state[0..SPONGE_RATE].to_vec();
+            self.output_buffer = self.sponge_state[0..HC::RATE].to_vec();
         }
 
         self.output_buffer
@@ -241,15 +316,17 @@ impl<F: RichField + Extendable<D>, H: AlgebraicHasher<F>, const D: usize>
             .expect("Output buffer should be non-empty")
     }
 
-    pub fn get_n_challenges(
+    pub fn get_n_challenges(&mut self, builder: &mut CircuitBuilder<F, D>, n: usize) -> Vec<Target>
-        &mut self,
+    where
-        builder: &mut CircuitBuilder<F, D>,
+        [(); HC::WIDTH]:,
-        n: usize,
+    {
-    ) -> Vec<Target> {
         (0..n).map(|_| self.get_challenge(builder)).collect()
     }
 
-    pub fn get_hash(&mut self, builder: &mut CircuitBuilder<F, D>) -> HashOutTarget {
+    pub fn get_hash(&mut self, builder: &mut CircuitBuilder<F, D>) -> HashOutTarget
+    where
+        [(); HC::WIDTH]:,
+    {
         HashOutTarget {
             elements: [
                 self.get_challenge(builder),
@@ -263,18 +340,24 @@ impl<F: RichField + Extendable<D>, H: AlgebraicHasher<F>, const D: usize>
     pub fn get_extension_challenge(
         &mut self,
         builder: &mut CircuitBuilder<F, D>,
-    ) -> ExtensionTarget<D> {
+    ) -> ExtensionTarget<D>
+    where
+        [(); HC::WIDTH]:,
+    {
         self.get_n_challenges(builder, D).try_into().unwrap()
     }
 
     /// Absorb any buffered inputs. After calling this, the input buffer will be empty, and the
     /// output buffer will be full.
-    fn absorb_buffered_inputs(&mut self, builder: &mut CircuitBuilder<F, D>) {
+    fn absorb_buffered_inputs(&mut self, builder: &mut CircuitBuilder<F, D>)
+    where
+        [(); HC::WIDTH]:,
+    {
         if self.input_buffer.is_empty() {
             return;
         }
 
-        for input_chunk in self.input_buffer.chunks(SPONGE_RATE) {
+        for input_chunk in self.input_buffer.chunks(HC::RATE) {
             // Overwrite the first r elements with the inputs. This differs from a standard sponge,
             // where we would xor or add in the inputs. This is a well-known variant, though,
             // sometimes called "overwrite mode".
@@ -283,15 +366,15 @@ impl<F: RichField + Extendable<D>, H: AlgebraicHasher<F>, const D: usize>
             }
 
             // Apply the permutation.
-            self.sponge_state = builder.permute::<H>(self.sponge_state);
+            self.sponge_state = builder.permute::<HC, H>(self.sponge_state);
         }
 
-        self.output_buffer = self.sponge_state[0..SPONGE_RATE].to_vec();
+        self.output_buffer = self.sponge_state[0..HC::RATE].to_vec();
 
         self.input_buffer.clear();
     }
 
-    pub fn compact(&mut self, builder: &mut CircuitBuilder<F, D>) -> [Target; SPONGE_WIDTH] {
+    pub fn compact(&mut self, builder: &mut CircuitBuilder<F, D>) -> [Target; HC::WIDTH] {
         self.absorb_buffered_inputs(builder);
         self.output_buffer.clear();
         self.sponge_state
@@ -314,7 +397,11 @@ mod tests {
         const D: usize = 2;
         type C = PoseidonGoldilocksConfig;
         type F = <C as GenericConfig<D>>::F;
-        let mut challenger = Challenger::<F, <C as GenericConfig<D>>::InnerHasher>::new();
+        let mut challenger = Challenger::<
+            F,
+            <C as GenericConfig<D>>::HCI,
+            <C as GenericConfig<D>>::InnerHasher,
+        >::new();
         let mut challenges = Vec::new();
 
         for i in 1..10 {
@@ -348,7 +435,11 @@ mod tests {
             .map(|&n| F::rand_vec(n))
             .collect();
 
-        let mut challenger = Challenger::<F, <C as GenericConfig<D>>::InnerHasher>::new();
+        let mut challenger = Challenger::<
+            F,
+            <C as GenericConfig<D>>::HCI,
+            <C as GenericConfig<D>>::InnerHasher,
+        >::new();
         let mut outputs_per_round: Vec<Vec<F>> = Vec::new();
         for (r, inputs) in inputs_per_round.iter().enumerate() {
             challenger.observe_elements(inputs);
@@ -357,8 +448,12 @@ mod tests {
 
         let config = CircuitConfig::standard_recursion_config();
         let mut builder = CircuitBuilder::<F, D>::new(config);
-        let mut recursive_challenger =
+        let mut recursive_challenger = RecursiveChallenger::<
-            RecursiveChallenger::<F, <C as GenericConfig<D>>::InnerHasher, D>::new(&mut builder);
+            F,
+            <C as GenericConfig<D>>::HCI,
+            <C as GenericConfig<D>>::InnerHasher,
+            D,
+        >::new(&mut builder);
         let mut recursive_outputs_per_round: Vec<Vec<Target>> = Vec::new();
         for (r, inputs) in inputs_per_round.iter().enumerate() {
             recursive_challenger.observe_elements(&builder.constants(inputs));

plonky2/src/iop/witness.rs

@@ -9,6 +9,7 @@ use crate::field::types::Field;
 use crate::fri::structure::{FriOpenings, FriOpeningsTarget};
 use crate::fri::witness_util::set_fri_proof_target;
 use crate::hash::hash_types::{HashOut, HashOutTarget, MerkleCapTarget, RichField};
+use crate::hash::hashing::HashConfig;
 use crate::hash::merkle_tree::MerkleCap;
 use crate::iop::ext_target::ExtensionTarget;
 use crate::iop::target::{BoolTarget, Target};
@@ -27,10 +28,10 @@ pub trait WitnessWrite<F: Field> {
             .for_each(|(&t, x)| self.set_target(t, x));
     }
 
-    fn set_cap_target<H: AlgebraicHasher<F>>(
+    fn set_cap_target<HC: HashConfig, H: AlgebraicHasher<F, HC>>(
         &mut self,
         ct: &MerkleCapTarget,
-        value: &MerkleCap<F, H>,
+        value: &MerkleCap<F, HC, H>,
     ) where
         F: RichField,
     {
@@ -77,7 +78,7 @@ pub trait WitnessWrite<F: Field> {
         proof_with_pis: &ProofWithPublicInputs<F, C, D>,
     ) where
         F: RichField + Extendable<D>,
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
     {
         let ProofWithPublicInputs {
             proof,
@@ -103,7 +104,7 @@ pub trait WitnessWrite<F: Field> {
         proof: &Proof<F, C, D>,
     ) where
         F: RichField + Extendable<D>,
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
     {
         self.set_cap_target(&proof_target.wires_cap, &proof.wires_cap);
         self.set_cap_target(
@@ -142,7 +143,7 @@ pub trait WitnessWrite<F: Field> {
         vd: &VerifierOnlyCircuitData<C, D>,
     ) where
         F: RichField + Extendable<D>,
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
     {
         self.set_cap_target(&vdt.constants_sigmas_cap, &vd.constants_sigmas_cap);
         self.set_hash_target(vdt.circuit_digest, vd.circuit_digest);
@@ -224,10 +225,14 @@ pub trait Witness<F: Field>: WitnessWrite<F> {
         }
     }
 
-    fn get_merkle_cap_target<H: Hasher<F>>(&self, cap_target: MerkleCapTarget) -> MerkleCap<F, H>
+    fn get_merkle_cap_target<HC, H: Hasher<F, HC>>(
+        &self,
+        cap_target: MerkleCapTarget,
+    ) -> MerkleCap<F, HC, H>
     where
         F: RichField,
-        H: AlgebraicHasher<F>,
+        HC: HashConfig,
+        H: AlgebraicHasher<F, HC>,
     {
         let cap = cap_target
             .0

plonky2/src/lib.rs

@@ -1,5 +1,7 @@
 #![allow(clippy::too_many_arguments)]
 #![allow(clippy::needless_range_loop)]
+#![allow(clippy::upper_case_acronyms)]
+#![feature(generic_const_exprs)]
 #![cfg_attr(not(feature = "std"), no_std)]
 
 extern crate alloc;

plonky2/src/plonk/circuit_builder.rs

@@ -28,6 +28,7 @@ use crate::gates::noop::NoopGate;
 use crate::gates::public_input::PublicInputGate;
 use crate::gates::selectors::selector_polynomials;
 use crate::hash::hash_types::{HashOut, HashOutTarget, MerkleCapTarget, RichField};
+use crate::hash::hashing::HashConfig;
 use crate::hash::merkle_proofs::MerkleProofTarget;
 use crate::hash::merkle_tree::MerkleCap;
 use crate::iop::ext_target::ExtensionTarget;
@@ -434,9 +435,9 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         }
     }
 
-    pub fn constant_merkle_cap<H: Hasher<F, Hash = HashOut<F>>>(
+    pub fn constant_merkle_cap<HC: HashConfig, H: Hasher<F, HC, Hash = HashOut<F>>>(
         &mut self,
-        cap: &MerkleCap<F, H>,
+        cap: &MerkleCap<F, HC, H>,
     ) -> MerkleCapTarget {
         MerkleCapTarget(cap.0.iter().map(|h| self.constant_hash(*h)).collect())
     }
@@ -446,7 +447,7 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         verifier_data: &VerifierOnlyCircuitData<C, D>,
     ) -> VerifierCircuitTarget
     where
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
     {
         VerifierCircuitTarget {
             constants_sigmas_cap: self.constant_merkle_cap(&verifier_data.constants_sigmas_cap),
@@ -737,7 +738,11 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
     }
 
     /// Builds a "full circuit", with both prover and verifier data.
-    pub fn build<C: GenericConfig<D, F = F>>(mut self) -> CircuitData<F, C, D> {
+    pub fn build<C: GenericConfig<D, F = F>>(mut self) -> CircuitData<F, C, D>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         let mut timing = TimingTree::new("preprocess", Level::Trace);
         #[cfg(feature = "std")]
         let start = Instant::now();
@@ -748,7 +753,7 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         // those hash wires match the claimed public inputs.
         let num_public_inputs = self.public_inputs.len();
         let public_inputs_hash =
-            self.hash_n_to_hash_no_pad::<C::InnerHasher>(self.public_inputs.clone());
+            self.hash_n_to_hash_no_pad::<C::HCI, C::InnerHasher>(self.public_inputs.clone());
         let pi_gate = self.add_gate(PublicInputGate, vec![]);
         for (&hash_part, wire) in public_inputs_hash
             .elements
@@ -825,7 +830,7 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         let fft_root_table = fft_root_table(max_fft_points);
 
         let constants_sigmas_vecs = [constant_vecs, sigma_vecs.clone()].concat();
-        let constants_sigmas_commitment = PolynomialBatch::from_values(
+        let constants_sigmas_commitment = PolynomialBatch::<F, C, D>::from_values(
             constants_sigmas_vecs,
             rate_bits,
             PlonkOracle::CONSTANTS_SIGMAS.blinding,
@@ -913,7 +918,7 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
             assert_eq!(goal_data, common, "The expected circuit data passed to cyclic recursion method did not match the actual circuit");
         }
 
-        let prover_only = ProverOnlyCircuitData {
+        let prover_only = ProverOnlyCircuitData::<F, C, D> {
             generators: self.generators,
             generator_indices_by_watches,
             constants_sigmas_commitment,
@@ -925,7 +930,7 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
             circuit_digest,
         };
 
-        let verifier_only = VerifierOnlyCircuitData {
+        let verifier_only = VerifierOnlyCircuitData::<C, D> {
             constants_sigmas_cap,
             circuit_digest,
         };
@@ -941,16 +946,24 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
     }
 
     /// Builds a "prover circuit", with data needed to generate proofs but not verify them.
-    pub fn build_prover<C: GenericConfig<D, F = F>>(self) -> ProverCircuitData<F, C, D> {
+    pub fn build_prover<C: GenericConfig<D, F = F>>(self) -> ProverCircuitData<F, C, D>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         // TODO: Can skip parts of this.
-        let circuit_data = self.build();
+        let circuit_data = self.build::<C>();
         circuit_data.prover_data()
     }
 
     /// Builds a "verifier circuit", with data needed to verify proofs but not generate them.
-    pub fn build_verifier<C: GenericConfig<D, F = F>>(self) -> VerifierCircuitData<F, C, D> {
+    pub fn build_verifier<C: GenericConfig<D, F = F>>(self) -> VerifierCircuitData<F, C, D>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         // TODO: Can skip parts of this.
-        let circuit_data = self.build();
+        let circuit_data = self.build::<C>();
         circuit_data.verifier_data()
     }
 }

plonky2/src/plonk/circuit_data.rs

@@ -19,6 +19,7 @@ use crate::fri::{FriConfig, FriParams};
 use crate::gates::gate::GateRef;
 use crate::gates::selectors::SelectorsInfo;
 use crate::hash::hash_types::{HashOutTarget, MerkleCapTarget, RichField};
+use crate::hash::hashing::HashConfig;
 use crate::hash::merkle_tree::MerkleCap;
 use crate::iop::ext_target::ExtensionTarget;
 use crate::iop::generator::WitnessGenerator;
@@ -115,8 +116,12 @@ pub struct CircuitData<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>,
 impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
     CircuitData<F, C, D>
 {
-    pub fn prove(&self, inputs: PartialWitness<F>) -> Result<ProofWithPublicInputs<F, C, D>> {
+    pub fn prove(&self, inputs: PartialWitness<F>) -> Result<ProofWithPublicInputs<F, C, D>>
-        prove(
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
+        prove::<F, C, D>(
             &self.prover_only,
             &self.common,
             inputs,
@@ -124,28 +129,44 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
         )
     }
 
-    pub fn verify(&self, proof_with_pis: ProofWithPublicInputs<F, C, D>) -> Result<()> {
+    pub fn verify(&self, proof_with_pis: ProofWithPublicInputs<F, C, D>) -> Result<()>
-        verify(proof_with_pis, &self.verifier_only, &self.common)
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
+        verify::<F, C, D>(proof_with_pis, &self.verifier_only, &self.common)
     }
 
     pub fn verify_compressed(
         &self,
         compressed_proof_with_pis: CompressedProofWithPublicInputs<F, C, D>,
-    ) -> Result<()> {
+    ) -> Result<()>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         compressed_proof_with_pis.verify(&self.verifier_only, &self.common)
     }
 
     pub fn compress(
         &self,
         proof: ProofWithPublicInputs<F, C, D>,
-    ) -> Result<CompressedProofWithPublicInputs<F, C, D>> {
+    ) -> Result<CompressedProofWithPublicInputs<F, C, D>>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         proof.compress(&self.verifier_only.circuit_digest, &self.common)
     }
 
     pub fn decompress(
         &self,
         proof: CompressedProofWithPublicInputs<F, C, D>,
-    ) -> Result<ProofWithPublicInputs<F, C, D>> {
+    ) -> Result<ProofWithPublicInputs<F, C, D>>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         proof.decompress(&self.verifier_only.circuit_digest, &self.common)
     }
 
@@ -193,8 +214,12 @@ pub struct ProverCircuitData<
 impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
     ProverCircuitData<F, C, D>
 {
-    pub fn prove(&self, inputs: PartialWitness<F>) -> Result<ProofWithPublicInputs<F, C, D>> {
+    pub fn prove(&self, inputs: PartialWitness<F>) -> Result<ProofWithPublicInputs<F, C, D>>
-        prove(
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
+        prove::<F, C, D>(
             &self.prover_only,
             &self.common,
             inputs,
@@ -217,14 +242,22 @@ pub struct VerifierCircuitData<
 impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
     VerifierCircuitData<F, C, D>
 {
-    pub fn verify(&self, proof_with_pis: ProofWithPublicInputs<F, C, D>) -> Result<()> {
+    pub fn verify(&self, proof_with_pis: ProofWithPublicInputs<F, C, D>) -> Result<()>
-        verify(proof_with_pis, &self.verifier_only, &self.common)
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
+        verify::<F, C, D>(proof_with_pis, &self.verifier_only, &self.common)
     }
 
     pub fn verify_compressed(
         &self,
         compressed_proof_with_pis: CompressedProofWithPublicInputs<F, C, D>,
-    ) -> Result<()> {
+    ) -> Result<()>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         compressed_proof_with_pis.verify(&self.verifier_only, &self.common)
     }
 }
@@ -254,17 +287,17 @@ pub struct ProverOnlyCircuitData<
     pub fft_root_table: Option<FftRootTable<F>>,
     /// A digest of the "circuit" (i.e. the instance, minus public inputs), which can be used to
     /// seed Fiat-Shamir.
-    pub circuit_digest: <<C as GenericConfig<D>>::Hasher as Hasher<F>>::Hash,
+    pub circuit_digest: <<C as GenericConfig<D>>::Hasher as Hasher<F, C::HCO>>::Hash,
 }
 
 /// Circuit data required by the verifier, but not the prover.
 #[derive(Debug, Clone, Eq, PartialEq)]
 pub struct VerifierOnlyCircuitData<C: GenericConfig<D>, const D: usize> {
     /// A commitment to each constant polynomial and each permutation polynomial.
-    pub constants_sigmas_cap: MerkleCap<C::F, C::Hasher>,
+    pub constants_sigmas_cap: MerkleCap<C::F, C::HCO, C::Hasher>,
     /// A digest of the "circuit" (i.e. the instance, minus public inputs), which can be used to
     /// seed Fiat-Shamir.
-    pub circuit_digest: <<C as GenericConfig<D>>::Hasher as Hasher<C::F>>::Hash,
+    pub circuit_digest: <<C as GenericConfig<D>>::Hasher as Hasher<C::F, C::HCO>>::Hash,
 }
 
 /// Circuit data required by both the prover and the verifier.

plonky2/src/plonk/config.rs

@@ -9,7 +9,7 @@ use crate::field::extension::quadratic::QuadraticExtension;
 use crate::field::extension::{Extendable, FieldExtension};
 use crate::field::goldilocks_field::GoldilocksField;
 use crate::hash::hash_types::{HashOut, RichField};
-use crate::hash::hashing::{PlonkyPermutation, SPONGE_WIDTH};
+use crate::hash::hashing::{HashConfig, PlonkyPermutation};
 use crate::hash::keccak::KeccakHash;
 use crate::hash::poseidon::PoseidonHash;
 use crate::iop::target::{BoolTarget, Target};
@@ -25,7 +25,7 @@ pub trait GenericHashOut<F: RichField>:
 }
 
 /// Trait for hash functions.
-pub trait Hasher<F: RichField>: Sized + Clone + Debug + Eq + PartialEq {
+pub trait Hasher<F: RichField, HC: HashConfig>: Sized + Clone + Debug + Eq + PartialEq {
     /// Size of `Hash` in bytes.
     const HASH_SIZE: usize;
 
@@ -33,17 +33,22 @@ pub trait Hasher<F: RichField>: Sized + Clone + Debug + Eq + PartialEq {
     type Hash: GenericHashOut<F>;
 
     /// Permutation used in the sponge construction.
-    type Permutation: PlonkyPermutation<F>;
+    type Permutation: PlonkyPermutation<F, HC>;
 
     /// Hash a message without any padding step. Note that this can enable length-extension attacks.
     /// However, it is still collision-resistant in cases where the input has a fixed length.
-    fn hash_no_pad(input: &[F]) -> Self::Hash;
+    fn hash_no_pad(input: &[F]) -> Self::Hash
+    where
+        [(); HC::WIDTH]:;
 
     /// Pad the message using the `pad10*1` rule, then hash it.
-    fn hash_pad(input: &[F]) -> Self::Hash {
+    fn hash_pad(input: &[F]) -> Self::Hash
+    where
+        [(); HC::WIDTH]:,
+    {
         let mut padded_input = input.to_vec();
         padded_input.push(F::ONE);
-        while (padded_input.len() + 1) % SPONGE_WIDTH != 0 {
+        while (padded_input.len() + 1) % HC::WIDTH != 0 {
             padded_input.push(F::ZERO);
         }
         padded_input.push(F::ONE);
@@ -52,7 +57,10 @@ pub trait Hasher<F: RichField>: Sized + Clone + Debug + Eq + PartialEq {
 
     /// Hash the slice if necessary to reduce its length to ~256 bits. If it already fits, this is a
     /// no-op.
-    fn hash_or_noop(inputs: &[F]) -> Self::Hash {
+    fn hash_or_noop(inputs: &[F]) -> Self::Hash
+    where
+        [(); HC::WIDTH]:,
+    {
         if inputs.len() * 8 <= Self::HASH_SIZE {
             let mut inputs_bytes = vec![0u8; Self::HASH_SIZE];
             for i in 0..inputs.len() {
@@ -65,22 +73,22 @@ pub trait Hasher<F: RichField>: Sized + Clone + Debug + Eq + PartialEq {
         }
     }
 
-    fn two_to_one(left: Self::Hash, right: Self::Hash) -> Self::Hash;
+    fn two_to_one(left: Self::Hash, right: Self::Hash) -> Self::Hash
+    where
+        [(); HC::WIDTH]:;
 }
 
 /// Trait for algebraic hash functions, built from a permutation using the sponge construction.
-pub trait AlgebraicHasher<F: RichField>: Hasher<F, Hash = HashOut<F>> {
+pub trait AlgebraicHasher<F: RichField, HC: HashConfig>: Hasher<F, HC, Hash = HashOut<F>> {
-    // TODO: Adding a `const WIDTH: usize` here yields a compiler error down the line.
-    // Maybe try again in a while.
-
     /// Circuit to conditionally swap two chunks of the inputs (useful in verifying Merkle proofs),
     /// then apply the permutation.
     fn permute_swapped<const D: usize>(
-        inputs: [Target; SPONGE_WIDTH],
+        inputs: [Target; HC::WIDTH],
         swap: BoolTarget,
         builder: &mut CircuitBuilder<F, D>,
-    ) -> [Target; SPONGE_WIDTH]
+    ) -> [Target; HC::WIDTH]
     where
+        [(); HC::WIDTH]:,
         F: RichField + Extendable<D>;
 }
 
@@ -92,28 +100,48 @@ pub trait GenericConfig<const D: usize>:
     type F: RichField + Extendable<D, Extension = Self::FE>;
     /// Field extension of degree D of the main field.
     type FE: FieldExtension<D, BaseField = Self::F>;
+    /// Hash configuration for this GenericConfig's `Hasher`.
+    type HCO: HashConfig;
+    /// Hash configuration for this GenericConfig's `InnerHasher`.
+    type HCI: HashConfig;
     /// Hash function used for building Merkle trees.
-    type Hasher: Hasher<Self::F>;
+    type Hasher: Hasher<Self::F, Self::HCO>;
     /// Algebraic hash function used for the challenger and hashing public inputs.
-    type InnerHasher: AlgebraicHasher<Self::F>;
+    type InnerHasher: AlgebraicHasher<Self::F, Self::HCI>;
 }
 
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct PoseidonHashConfig;
+impl HashConfig for PoseidonHashConfig {
+    const RATE: usize = 8;
+    const WIDTH: usize = 12;
+}
 /// Configuration using Poseidon over the Goldilocks field.
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub struct PoseidonGoldilocksConfig;
 impl GenericConfig<2> for PoseidonGoldilocksConfig {
     type F = GoldilocksField;
     type FE = QuadraticExtension<Self::F>;
+    type HCO = PoseidonHashConfig;
+    type HCI = PoseidonHashConfig;
     type Hasher = PoseidonHash;
     type InnerHasher = PoseidonHash;
 }
 
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct KeccakHashConfig;
+impl HashConfig for KeccakHashConfig {
+    const RATE: usize = 8;
+    const WIDTH: usize = 12;
+}
 /// Configuration using truncated Keccak over the Goldilocks field.
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub struct KeccakGoldilocksConfig;
 impl GenericConfig<2> for KeccakGoldilocksConfig {
     type F = GoldilocksField;
     type FE = QuadraticExtension<Self::F>;
+    type HCO = KeccakHashConfig;
+    type HCI = PoseidonHashConfig;
     type Hasher = KeccakHash<25>;
     type InnerHasher = PoseidonHash;
 }

plonky2/src/plonk/get_challenges.rs

@@ -9,6 +9,7 @@ use crate::fri::proof::{CompressedFriProof, FriChallenges, FriProof, FriProofTar
 use crate::fri::verifier::{compute_evaluation, fri_combine_initial, PrecomputedReducedOpenings};
 use crate::gadgets::polynomial::PolynomialCoeffsExtTarget;
 use crate::hash::hash_types::{HashOutTarget, MerkleCapTarget, RichField};
+use crate::hash::hashing::HashConfig;
 use crate::hash::merkle_tree::MerkleCap;
 use crate::iop::challenger::{Challenger, RecursiveChallenger};
 use crate::iop::target::Target;
@@ -23,34 +24,38 @@ use crate::plonk::proof::{
 use crate::util::reverse_bits;
 
 fn get_challenges<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>(
-    public_inputs_hash: <<C as GenericConfig<D>>::InnerHasher as Hasher<F>>::Hash,
+    public_inputs_hash: <<C as GenericConfig<D>>::InnerHasher as Hasher<F, C::HCI>>::Hash,
-    wires_cap: &MerkleCap<F, C::Hasher>,
+    wires_cap: &MerkleCap<F, C::HCO, C::Hasher>,
-    plonk_zs_partial_products_cap: &MerkleCap<F, C::Hasher>,
+    plonk_zs_partial_products_cap: &MerkleCap<F, C::HCO, C::Hasher>,
-    quotient_polys_cap: &MerkleCap<F, C::Hasher>,
+    quotient_polys_cap: &MerkleCap<F, C::HCO, C::Hasher>,
     openings: &OpeningSet<F, D>,
-    commit_phase_merkle_caps: &[MerkleCap<F, C::Hasher>],
+    commit_phase_merkle_caps: &[MerkleCap<F, C::HCO, C::Hasher>],
     final_poly: &PolynomialCoeffs<F::Extension>,
     pow_witness: F,
-    circuit_digest: &<<C as GenericConfig<D>>::Hasher as Hasher<C::F>>::Hash,
+    circuit_digest: &<<C as GenericConfig<D>>::Hasher as Hasher<C::F, C::HCO>>::Hash,
     common_data: &CommonCircuitData<F, D>,
-) -> anyhow::Result<ProofChallenges<F, D>> {
+) -> anyhow::Result<ProofChallenges<F, D>>
+where
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
+{
     let config = &common_data.config;
     let num_challenges = config.num_challenges;
 
-    let mut challenger = Challenger::<F, C::Hasher>::new();
+    let mut challenger = Challenger::<F, C::HCO, C::Hasher>::new();
 
     // Observe the instance.
-    challenger.observe_hash::<C::Hasher>(*circuit_digest);
+    challenger.observe_hash::<C::HCO, C::Hasher>(*circuit_digest);
-    challenger.observe_hash::<C::InnerHasher>(public_inputs_hash);
+    challenger.observe_hash::<C::HCI, C::InnerHasher>(public_inputs_hash);
 
-    challenger.observe_cap(wires_cap);
+    challenger.observe_cap::<C::HCO, C::Hasher>(wires_cap);
     let plonk_betas = challenger.get_n_challenges(num_challenges);
     let plonk_gammas = challenger.get_n_challenges(num_challenges);
 
-    challenger.observe_cap(plonk_zs_partial_products_cap);
+    challenger.observe_cap::<C::HCO, C::Hasher>(plonk_zs_partial_products_cap);
     let plonk_alphas = challenger.get_n_challenges(num_challenges);
 
-    challenger.observe_cap(quotient_polys_cap);
+    challenger.observe_cap::<C::HCO, C::Hasher>(quotient_polys_cap);
     let plonk_zeta = challenger.get_extension_challenge::<D>();
 
     challenger.observe_openings(&openings.to_fri_openings());
@@ -75,9 +80,13 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
 {
     pub(crate) fn fri_query_indices(
         &self,
-        circuit_digest: &<<C as GenericConfig<D>>::Hasher as Hasher<C::F>>::Hash,
+        circuit_digest: &<<C as GenericConfig<D>>::Hasher as Hasher<C::F, C::HCO>>::Hash,
         common_data: &CommonCircuitData<F, D>,
-    ) -> anyhow::Result<Vec<usize>> {
+    ) -> anyhow::Result<Vec<usize>>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         Ok(self
             .get_challenges(self.get_public_inputs_hash(), circuit_digest, common_data)?
             .fri_challenges
@@ -87,10 +96,14 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
     /// Computes all Fiat-Shamir challenges used in the Plonk proof.
     pub(crate) fn get_challenges(
         &self,
-        public_inputs_hash: <<C as GenericConfig<D>>::InnerHasher as Hasher<F>>::Hash,
+        public_inputs_hash: <<C as GenericConfig<D>>::InnerHasher as Hasher<F, C::HCI>>::Hash,
-        circuit_digest: &<<C as GenericConfig<D>>::Hasher as Hasher<C::F>>::Hash,
+        circuit_digest: &<<C as GenericConfig<D>>::Hasher as Hasher<C::F, C::HCO>>::Hash,
         common_data: &CommonCircuitData<F, D>,
-    ) -> anyhow::Result<ProofChallenges<F, D>> {
+    ) -> anyhow::Result<ProofChallenges<F, D>>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         let Proof {
             wires_cap,
             plonk_zs_partial_products_cap,
@@ -126,10 +139,14 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
     /// Computes all Fiat-Shamir challenges used in the Plonk proof.
     pub(crate) fn get_challenges(
         &self,
-        public_inputs_hash: <<C as GenericConfig<D>>::InnerHasher as Hasher<F>>::Hash,
+        public_inputs_hash: <<C as GenericConfig<D>>::InnerHasher as Hasher<F, C::HCI>>::Hash,
-        circuit_digest: &<<C as GenericConfig<D>>::Hasher as Hasher<C::F>>::Hash,
+        circuit_digest: &<<C as GenericConfig<D>>::Hasher as Hasher<C::F, C::HCO>>::Hash,
         common_data: &CommonCircuitData<F, D>,
-    ) -> anyhow::Result<ProofChallenges<F, D>> {
+    ) -> anyhow::Result<ProofChallenges<F, D>>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         let CompressedProof {
             wires_cap,
             plonk_zs_partial_products_cap,
@@ -249,12 +266,14 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         inner_common_data: &CommonCircuitData<F, D>,
     ) -> ProofChallengesTarget<D>
     where
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
     {
         let config = &inner_common_data.config;
         let num_challenges = config.num_challenges;
 
-        let mut challenger = RecursiveChallenger::<F, C::Hasher, D>::new(self);
+        let mut challenger = RecursiveChallenger::<F, C::HCO, C::Hasher, D>::new(self);
 
         // Observe the instance.
         challenger.observe_hash(&inner_circuit_digest);
@@ -297,7 +316,9 @@ impl<const D: usize> ProofWithPublicInputsTarget<D> {
         inner_common_data: &CommonCircuitData<F, D>,
     ) -> ProofChallengesTarget<D>
     where
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
     {
         let ProofTarget {
             wires_cap,

plonky2/src/plonk/proof.rs

@@ -15,6 +15,7 @@ use crate::fri::structure::{
 };
 use crate::fri::FriParams;
 use crate::hash::hash_types::{MerkleCapTarget, RichField};
+use crate::hash::hashing::HashConfig;
 use crate::hash::merkle_tree::MerkleCap;
 use crate::iop::ext_target::ExtensionTarget;
 use crate::iop::target::Target;
@@ -29,15 +30,15 @@ use crate::util::serialization::{Buffer, Read};
 #[serde(bound = "")]
 pub struct Proof<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize> {
     /// Merkle cap of LDEs of wire values.
-    pub wires_cap: MerkleCap<F, C::Hasher>,
+    pub wires_cap: MerkleCap<F, C::HCO, C::Hasher>,
     /// Merkle cap of LDEs of Z, in the context of Plonk's permutation argument.
-    pub plonk_zs_partial_products_cap: MerkleCap<F, C::Hasher>,
+    pub plonk_zs_partial_products_cap: MerkleCap<F, C::HCO, C::Hasher>,
     /// Merkle cap of LDEs of the quotient polynomial components.
-    pub quotient_polys_cap: MerkleCap<F, C::Hasher>,
+    pub quotient_polys_cap: MerkleCap<F, C::HCO, C::Hasher>,
     /// Purported values of each polynomial at the challenge point.
     pub openings: OpeningSet<F, D>,
     /// A batch FRI argument for all openings.
-    pub opening_proof: FriProof<F, C::Hasher, D>,
+    pub opening_proof: FriProof<F, C::HCO, C::Hasher, D>,
 }
 
 #[derive(Clone, Debug)]
@@ -86,9 +87,13 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
 {
     pub fn compress(
         self,
-        circuit_digest: &<<C as GenericConfig<D>>::Hasher as Hasher<C::F>>::Hash,
+        circuit_digest: &<<C as GenericConfig<D>>::Hasher as Hasher<C::F, C::HCO>>::Hash,
         common_data: &CommonCircuitData<F, D>,
-    ) -> anyhow::Result<CompressedProofWithPublicInputs<F, C, D>> {
+    ) -> anyhow::Result<CompressedProofWithPublicInputs<F, C, D>>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         let indices = self.fri_query_indices(circuit_digest, common_data)?;
         let compressed_proof = self.proof.compress(&indices, &common_data.fri_params);
         Ok(CompressedProofWithPublicInputs {
@@ -99,7 +104,10 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
 
     pub(crate) fn get_public_inputs_hash(
         &self,
-    ) -> <<C as GenericConfig<D>>::InnerHasher as Hasher<F>>::Hash {
+    ) -> <<C as GenericConfig<D>>::InnerHasher as Hasher<F, C::HCI>>::Hash
+    where
+        [(); C::HCI::WIDTH]:,
+    {
         C::InnerHasher::hash_no_pad(&self.public_inputs)
     }
 
@@ -129,15 +137,15 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
 pub struct CompressedProof<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
 {
     /// Merkle cap of LDEs of wire values.
-    pub wires_cap: MerkleCap<F, C::Hasher>,
+    pub wires_cap: MerkleCap<F, C::HCO, C::Hasher>,
     /// Merkle cap of LDEs of Z, in the context of Plonk's permutation argument.
-    pub plonk_zs_partial_products_cap: MerkleCap<F, C::Hasher>,
+    pub plonk_zs_partial_products_cap: MerkleCap<F, C::HCO, C::Hasher>,
     /// Merkle cap of LDEs of the quotient polynomial components.
-    pub quotient_polys_cap: MerkleCap<F, C::Hasher>,
+    pub quotient_polys_cap: MerkleCap<F, C::HCO, C::Hasher>,
     /// Purported values of each polynomial at the challenge point.
     pub openings: OpeningSet<F, D>,
     /// A compressed batch FRI argument for all openings.
-    pub opening_proof: CompressedFriProof<F, C::Hasher, D>,
+    pub opening_proof: CompressedFriProof<F, C::HCO, C::Hasher, D>,
 }
 
 impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
@@ -149,7 +157,10 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
         challenges: &ProofChallenges<F, D>,
         fri_inferred_elements: FriInferredElements<F, D>,
         params: &FriParams,
-    ) -> Proof<F, C, D> {
+    ) -> Proof<F, C, D>
+    where
+        [(); C::HCO::WIDTH]:,
+    {
         let CompressedProof {
             wires_cap,
             plonk_zs_partial_products_cap,
@@ -184,9 +195,13 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
 {
     pub fn decompress(
         self,
-        circuit_digest: &<<C as GenericConfig<D>>::Hasher as Hasher<C::F>>::Hash,
+        circuit_digest: &<<C as GenericConfig<D>>::Hasher as Hasher<C::F, C::HCO>>::Hash,
         common_data: &CommonCircuitData<F, D>,
-    ) -> anyhow::Result<ProofWithPublicInputs<F, C, D>> {
+    ) -> anyhow::Result<ProofWithPublicInputs<F, C, D>>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         let challenges =
             self.get_challenges(self.get_public_inputs_hash(), circuit_digest, common_data)?;
         let fri_inferred_elements = self.get_inferred_elements(&challenges, common_data);
@@ -203,7 +218,11 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
         self,
         verifier_data: &VerifierOnlyCircuitData<C, D>,
         common_data: &CommonCircuitData<F, D>,
-    ) -> anyhow::Result<()> {
+    ) -> anyhow::Result<()>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         ensure!(
             self.public_inputs.len() == common_data.num_public_inputs,
             "Number of public inputs doesn't match circuit data."
@@ -218,7 +237,7 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
         let decompressed_proof =
             self.proof
                 .decompress(&challenges, fri_inferred_elements, &common_data.fri_params);
-        verify_with_challenges(
+        verify_with_challenges::<F, C, D>(
             decompressed_proof,
             public_inputs_hash,
             challenges,
@@ -229,7 +248,10 @@ impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>
 
     pub(crate) fn get_public_inputs_hash(
         &self,
-    ) -> <<C as GenericConfig<D>>::InnerHasher as Hasher<F>>::Hash {
+    ) -> <<C as GenericConfig<D>>::InnerHasher as Hasher<F, C::HCI>>::Hash
+    where
+        [(); C::HCI::WIDTH]:,
+    {
         C::InnerHasher::hash_no_pad(&self.public_inputs)
     }
 

plonky2/src/plonk/prover.rs

@@ -11,6 +11,7 @@ use crate::field::types::Field;
 use crate::field::zero_poly_coset::ZeroPolyOnCoset;
 use crate::fri::oracle::PolynomialBatch;
 use crate::hash::hash_types::RichField;
+use crate::hash::hashing::HashConfig;
 use crate::iop::challenger::Challenger;
 use crate::iop::generator::generate_partial_witness;
 use crate::iop::witness::{MatrixWitness, PartialWitness, Witness};
@@ -30,7 +31,13 @@ pub fn prove<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D:
     common_data: &CommonCircuitData<F, D>,
     inputs: PartialWitness<F>,
     timing: &mut TimingTree,
-) -> Result<ProofWithPublicInputs<F, C, D>> {
+) -> Result<ProofWithPublicInputs<F, C, D>>
+where
+    C::Hasher: Hasher<F, C::HCO>,
+    C::InnerHasher: Hasher<F, C::HCI>,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
+{
     let config = &common_data.config;
     let num_challenges = config.num_challenges;
     let quotient_degree = common_data.quotient_degree();
@@ -64,7 +71,7 @@ pub fn prove<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D:
     let wires_commitment = timed!(
         timing,
         "compute wires commitment",
-        PolynomialBatch::from_values(
+        PolynomialBatch::<F, C, D>::from_values(
             wires_values,
             config.fri_config.rate_bits,
             config.zero_knowledge && PlonkOracle::WIRES.blinding,
@@ -74,13 +81,13 @@ pub fn prove<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D:
         )
     );
 
-    let mut challenger = Challenger::<F, C::Hasher>::new();
+    let mut challenger = Challenger::<F, C::HCO, C::Hasher>::new();
 
     // Observe the instance.
-    challenger.observe_hash::<C::Hasher>(prover_data.circuit_digest);
+    challenger.observe_hash::<C::HCO, C::Hasher>(prover_data.circuit_digest);
-    challenger.observe_hash::<C::InnerHasher>(public_inputs_hash);
+    challenger.observe_hash::<C::HCI, C::InnerHasher>(public_inputs_hash);
 
-    challenger.observe_cap(&wires_commitment.merkle_tree.cap);
+    challenger.observe_cap::<C::HCO, C::Hasher>(&wires_commitment.merkle_tree.cap);
     let betas = challenger.get_n_challenges(num_challenges);
     let gammas = challenger.get_n_challenges(num_challenges);
 
@@ -104,7 +111,7 @@ pub fn prove<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D:
     let partial_products_and_zs_commitment = timed!(
         timing,
         "commit to partial products and Z's",
-        PolynomialBatch::from_values(
+        PolynomialBatch::<F, C, D>::from_values(
             zs_partial_products,
             config.fri_config.rate_bits,
             config.zero_knowledge && PlonkOracle::ZS_PARTIAL_PRODUCTS.blinding,
@@ -114,14 +121,15 @@ pub fn prove<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D:
         )
     );
 
-    challenger.observe_cap(&partial_products_and_zs_commitment.merkle_tree.cap);
+    challenger
+        .observe_cap::<C::HCO, C::Hasher>(&partial_products_and_zs_commitment.merkle_tree.cap);
 
     let alphas = challenger.get_n_challenges(num_challenges);
 
     let quotient_polys = timed!(
         timing,
         "compute quotient polys",
-        compute_quotient_polys(
+        compute_quotient_polys::<F, C, D>(
             common_data,
             prover_data,
             &public_inputs_hash,
@@ -152,7 +160,7 @@ pub fn prove<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D:
     let quotient_polys_commitment = timed!(
         timing,
         "commit to quotient polys",
-        PolynomialBatch::from_coeffs(
+        PolynomialBatch::<F, C, D>::from_coeffs(
             all_quotient_poly_chunks,
             config.fri_config.rate_bits,
             config.zero_knowledge && PlonkOracle::QUOTIENT.blinding,
@@ -162,7 +170,7 @@ pub fn prove<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D:
         )
     );
 
-    challenger.observe_cap(&quotient_polys_commitment.merkle_tree.cap);
+    challenger.observe_cap::<C::HCO, C::Hasher>(&quotient_polys_commitment.merkle_tree.cap);
 
     let zeta = challenger.get_extension_challenge::<D>();
     // To avoid leaking witness data, we want to ensure that our opening locations, `zeta` and
@@ -177,7 +185,7 @@ pub fn prove<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D:
     let openings = timed!(
         timing,
         "construct the opening set",
-        OpeningSet::new(
+        OpeningSet::new::<C>(
             zeta,
             g,
             &prover_data.constants_sigmas_commitment,
@@ -192,7 +200,7 @@ pub fn prove<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D:
     let opening_proof = timed!(
         timing,
         "compute opening proofs",
-        PolynomialBatch::prove_openings(
+        PolynomialBatch::<F, C, D>::prove_openings(
             &common_data.get_fri_instance(zeta),
             &[
                 &prover_data.constants_sigmas_commitment,
@@ -206,14 +214,14 @@ pub fn prove<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D:
         )
     );
 
-    let proof = Proof {
+    let proof = Proof::<F, C, D> {
         wires_cap: wires_commitment.merkle_tree.cap,
         plonk_zs_partial_products_cap: partial_products_and_zs_commitment.merkle_tree.cap,
         quotient_polys_cap: quotient_polys_commitment.merkle_tree.cap,
         openings,
         opening_proof,
     };
-    Ok(ProofWithPublicInputs {
+    Ok(ProofWithPublicInputs::<F, C, D> {
         proof,
         public_inputs,
     })
@@ -316,7 +324,7 @@ fn compute_quotient_polys<
 >(
     common_data: &CommonCircuitData<F, D>,
     prover_data: &'a ProverOnlyCircuitData<F, C, D>,
-    public_inputs_hash: &<<C as GenericConfig<D>>::InnerHasher as Hasher<F>>::Hash,
+    public_inputs_hash: &<<C as GenericConfig<D>>::InnerHasher as Hasher<F, C::HCI>>::Hash,
     wires_commitment: &'a PolynomialBatch<F, C, D>,
     zs_partial_products_commitment: &'a PolynomialBatch<F, C, D>,
     betas: &[F],

plonky2/src/plonk/verifier.rs

@@ -4,6 +4,7 @@ use crate::field::extension::Extendable;
 use crate::field::types::Field;
 use crate::fri::verifier::verify_fri_proof;
 use crate::hash::hash_types::RichField;
+use crate::hash::hashing::HashConfig;
 use crate::plonk::circuit_data::{CommonCircuitData, VerifierOnlyCircuitData};
 use crate::plonk::config::{GenericConfig, Hasher};
 use crate::plonk::plonk_common::reduce_with_powers;
@@ -16,7 +17,11 @@ pub(crate) fn verify<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, c
     proof_with_pis: ProofWithPublicInputs<F, C, D>,
     verifier_data: &VerifierOnlyCircuitData<C, D>,
     common_data: &CommonCircuitData<F, D>,
-) -> Result<()> {
+) -> Result<()>
+where
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
+{
     validate_proof_with_pis_shape(&proof_with_pis, common_data)?;
 
     let public_inputs_hash = proof_with_pis.get_public_inputs_hash();
@@ -26,7 +31,7 @@ pub(crate) fn verify<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, c
         common_data,
     )?;
 
-    verify_with_challenges(
+    verify_with_challenges::<F, C, D>(
         proof_with_pis.proof,
         public_inputs_hash,
         challenges,
@@ -41,11 +46,14 @@ pub(crate) fn verify_with_challenges<
     const D: usize,
 >(
     proof: Proof<F, C, D>,
-    public_inputs_hash: <<C as GenericConfig<D>>::InnerHasher as Hasher<F>>::Hash,
+    public_inputs_hash: <<C as GenericConfig<D>>::InnerHasher as Hasher<F, C::HCI>>::Hash,
     challenges: ProofChallenges<F, D>,
     verifier_data: &VerifierOnlyCircuitData<C, D>,
     common_data: &CommonCircuitData<F, D>,
-) -> Result<()> {
+) -> Result<()>
+where
+    [(); C::HCO::WIDTH]:,
+{
     let local_constants = &proof.openings.constants;
     let local_wires = &proof.openings.wires;
     let vars = EvaluationVars {

plonky2/src/recursion/conditional_recursive_verifier.rs

@@ -8,6 +8,7 @@ use crate::fri::proof::{
 };
 use crate::gadgets::polynomial::PolynomialCoeffsExtTarget;
 use crate::hash::hash_types::{HashOutTarget, MerkleCapTarget, RichField};
+use crate::hash::hashing::HashConfig;
 use crate::hash::merkle_proofs::MerkleProofTarget;
 use crate::iop::ext_target::ExtensionTarget;
 use crate::iop::target::{BoolTarget, Target};
@@ -29,7 +30,9 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         inner_verifier_data1: &VerifierCircuitTarget,
         inner_common_data: &CommonCircuitData<F, D>,
     ) where
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
     {
         let selected_proof =
             self.select_proof_with_pis(condition, proof_with_pis0, proof_with_pis1);
@@ -58,7 +61,9 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         inner_common_data: &CommonCircuitData<F, D>,
     ) -> anyhow::Result<()>
     where
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
     {
         let (dummy_proof_with_pis_target, dummy_verifier_data_target) =
             self.dummy_proof_and_vk::<C>(inner_common_data)?;

plonky2/src/recursion/cyclic_recursion.rs

@@ -4,6 +4,7 @@ use anyhow::{ensure, Result};
 
 use crate::field::extension::Extendable;
 use crate::hash::hash_types::{HashOut, HashOutTarget, MerkleCapTarget, RichField};
+use crate::hash::hashing::HashConfig;
 use crate::hash::merkle_tree::MerkleCap;
 use crate::iop::target::{BoolTarget, Target};
 use crate::plonk::circuit_builder::CircuitBuilder;
@@ -16,7 +17,7 @@ use crate::plonk::proof::{ProofWithPublicInputs, ProofWithPublicInputsTarget};
 impl<C: GenericConfig<D>, const D: usize> VerifierOnlyCircuitData<C, D> {
     fn from_slice(slice: &[C::F], common_data: &CommonCircuitData<C::F, D>) -> Result<Self>
     where
-        C::Hasher: AlgebraicHasher<C::F>,
+        C::Hasher: AlgebraicHasher<C::F, C::HCO>,
     {
         // The structure of the public inputs is `[..., circuit_digest, constants_sigmas_cap]`.
         let cap_len = common_data.config.fri_config.num_cap_elements();
@@ -88,7 +89,9 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         common_data: &CommonCircuitData<F, D>,
     ) -> Result<()>
     where
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
     {
         let verifier_data = self
             .verifier_data_public_input
@@ -140,7 +143,9 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         common_data: &CommonCircuitData<F, D>,
     ) -> Result<()>
     where
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
     {
         let (dummy_proof_with_pis_target, dummy_verifier_data_target) =
             self.dummy_proof_and_vk::<C>(common_data)?;
@@ -167,7 +172,9 @@ pub fn check_cyclic_proof_verifier_data<
     common_data: &CommonCircuitData<F, D>,
 ) -> Result<()>
 where
-    C::Hasher: AlgebraicHasher<F>,
+    C::Hasher: AlgebraicHasher<F, C::HCO>,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     let pis = VerifierOnlyCircuitData::<C, D>::from_slice(&proof.public_inputs, common_data)?;
     ensure!(verifier_data.constants_sigmas_cap == pis.constants_sigmas_cap);
@@ -184,12 +191,14 @@ mod tests {
     use crate::field::types::{Field, PrimeField64};
     use crate::gates::noop::NoopGate;
     use crate::hash::hash_types::{HashOutTarget, RichField};
-    use crate::hash::hashing::hash_n_to_hash_no_pad;
+    use crate::hash::hashing::{hash_n_to_hash_no_pad, HashConfig};
     use crate::hash::poseidon::{PoseidonHash, PoseidonPermutation};
     use crate::iop::witness::{PartialWitness, WitnessWrite};
     use crate::plonk::circuit_builder::CircuitBuilder;
     use crate::plonk::circuit_data::{CircuitConfig, CommonCircuitData};
-    use crate::plonk::config::{AlgebraicHasher, GenericConfig, PoseidonGoldilocksConfig};
+    use crate::plonk::config::{
+        AlgebraicHasher, GenericConfig, PoseidonGoldilocksConfig, PoseidonHashConfig,
+    };
     use crate::recursion::cyclic_recursion::check_cyclic_proof_verifier_data;
     use crate::recursion::dummy_circuit::cyclic_base_proof;
 
@@ -200,7 +209,9 @@ mod tests {
         const D: usize,
     >() -> CommonCircuitData<F, D>
     where
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
     {
         let config = CircuitConfig::standard_recursion_config();
         let builder = CircuitBuilder::<F, D>::new(config);
@@ -245,8 +256,9 @@ mod tests {
         let initial_hash_target = builder.add_virtual_hash();
         builder.register_public_inputs(&initial_hash_target.elements);
         let current_hash_in = builder.add_virtual_hash();
-        let current_hash_out =
+        let current_hash_out = builder.hash_n_to_hash_no_pad::<PoseidonHashConfig, PoseidonHash>(
-            builder.hash_n_to_hash_no_pad::<PoseidonHash>(current_hash_in.elements.to_vec());
+            current_hash_in.elements.to_vec(),
+        );
         builder.register_public_inputs(&current_hash_out.elements);
         let counter = builder.add_virtual_public_input();
 
@@ -347,7 +359,8 @@ mod tests {
     fn iterate_poseidon<F: RichField>(initial_state: [F; 4], n: usize) -> [F; 4] {
         let mut current = initial_state;
         for _ in 0..n {
-            current = hash_n_to_hash_no_pad::<F, PoseidonPermutation>(&current).elements;
+            current = hash_n_to_hash_no_pad::<F, PoseidonHashConfig, PoseidonPermutation>(&current)
+                .elements;
         }
         current
     }

plonky2/src/recursion/dummy_circuit.rs

@@ -7,6 +7,7 @@ use plonky2_util::ceil_div_usize;
 
 use crate::gates::noop::NoopGate;
 use crate::hash::hash_types::RichField;
+use crate::hash::hashing::HashConfig;
 use crate::iop::generator::{GeneratedValues, SimpleGenerator};
 use crate::iop::target::Target;
 use crate::iop::witness::{PartialWitness, PartitionWitness, WitnessWrite};
@@ -30,7 +31,9 @@ pub fn cyclic_base_proof<F, C, const D: usize>(
 where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F>,
-    C::Hasher: AlgebraicHasher<C::F>,
+    C::Hasher: AlgebraicHasher<C::F, C::HCO>,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     let pis_len = common_data.num_public_inputs;
     let cap_elements = common_data.config.fri_config.num_cap_elements();
@@ -46,19 +49,27 @@ where
 
     // TODO: A bit wasteful to build a dummy circuit here. We could potentially use a proof that
     // just consists of zeros, apart from public inputs.
-    dummy_proof(&dummy_circuit(common_data), nonzero_public_inputs).unwrap()
+    dummy_proof::<F, C, D>(
+        &dummy_circuit::<F, C, D>(common_data),
+        nonzero_public_inputs,
+    )
+    .unwrap()
 }
 
 /// Generate a proof for a dummy circuit. The `public_inputs` parameter let the caller specify
 /// certain public inputs (identified by their indices) which should be given specific values.
 /// The rest will default to zero.
-pub(crate) fn dummy_proof<F, C, const D: usize>(
+pub(crate) fn dummy_proof<
+    F: RichField + Extendable<D>,
+    C: GenericConfig<D, F = F>,
+    const D: usize,
+>(
     circuit: &CircuitData<F, C, D>,
     nonzero_public_inputs: HashMap<usize, F>,
 ) -> anyhow::Result<ProofWithPublicInputs<F, C, D>>
 where
-    F: RichField + Extendable<D>,
+    [(); C::HCO::WIDTH]:,
-    C: GenericConfig<D, F = F>,
+    [(); C::HCI::WIDTH]:,
 {
     let mut pw = PartialWitness::new();
     for i in 0..circuit.common.num_public_inputs {
@@ -75,7 +86,11 @@ pub(crate) fn dummy_circuit<
     const D: usize,
 >(
     common_data: &CommonCircuitData<F, D>,
-) -> CircuitData<F, C, D> {
+) -> CircuitData<F, C, D>
+where
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
+{
     let config = common_data.config.clone();
     assert!(
         !common_data.config.zero_knowledge,
@@ -109,10 +124,12 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         common_data: &CommonCircuitData<F, D>,
     ) -> anyhow::Result<(ProofWithPublicInputsTarget<D>, VerifierCircuitTarget)>
     where
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
     {
         let dummy_circuit = dummy_circuit::<F, C, D>(common_data);
-        let dummy_proof_with_pis = dummy_proof(&dummy_circuit, HashMap::new())?;
+        let dummy_proof_with_pis = dummy_proof::<F, C, D>(&dummy_circuit, HashMap::new())?;
         let dummy_proof_with_pis_target = self.add_virtual_proof_with_pis(common_data);
         let dummy_verifier_data_target =
             self.add_virtual_verifier_data(self.config.fri_config.cap_height);
@@ -144,7 +161,7 @@ impl<F, C, const D: usize> SimpleGenerator<F> for DummyProofGenerator<F, C, D>
 where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F> + 'static,
-    C::Hasher: AlgebraicHasher<F>,
+    C::Hasher: AlgebraicHasher<F, C::HCO>,
 {
     fn dependencies(&self) -> Vec<Target> {
         vec![]

plonky2/src/recursion/recursive_verifier.rs

@@ -1,5 +1,6 @@
 use crate::field::extension::Extendable;
 use crate::hash::hash_types::{HashOutTarget, RichField};
+use crate::hash::hashing::HashConfig;
 use crate::plonk::circuit_builder::CircuitBuilder;
 use crate::plonk::circuit_data::{CommonCircuitData, VerifierCircuitTarget};
 use crate::plonk::config::{AlgebraicHasher, GenericConfig};
@@ -20,14 +21,16 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         inner_verifier_data: &VerifierCircuitTarget,
         inner_common_data: &CommonCircuitData<F, D>,
     ) where
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
     {
         assert_eq!(
             proof_with_pis.public_inputs.len(),
             inner_common_data.num_public_inputs
         );
-        let public_inputs_hash =
+        let public_inputs_hash = self
-            self.hash_n_to_hash_no_pad::<C::InnerHasher>(proof_with_pis.public_inputs.clone());
+            .hash_n_to_hash_no_pad::<C::HCI, C::InnerHasher>(proof_with_pis.public_inputs.clone());
         let challenges = proof_with_pis.get_challenges::<F, C>(
             self,
             public_inputs_hash,
@@ -53,7 +56,8 @@ impl<F: RichField + Extendable<D>, const D: usize> CircuitBuilder<F, D> {
         inner_verifier_data: &VerifierCircuitTarget,
         inner_common_data: &CommonCircuitData<F, D>,
     ) where
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
+        [(); C::HCO::WIDTH]:,
     {
         let one = self.one_extension();
 
@@ -254,7 +258,8 @@ mod tests {
         assert_eq!(cd.degree_bits(), 12);
 
         // A standard recursive proof.
-        let (proof, vd, cd) = recursive_proof(proof, vd, cd, &standard_config, None, false, false)?;
+        let (proof, vd, cd) =
+            recursive_proof::<F, C, C, D>(proof, vd, cd, &standard_config, None, false, false)?;
         assert_eq!(cd.degree_bits(), 12);
 
         // A high-rate recursive proof, designed to be verifiable with fewer routed wires.
@@ -324,7 +329,11 @@ mod tests {
     fn dummy_proof<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize>(
         config: &CircuitConfig,
         num_dummy_gates: u64,
-    ) -> Result<Proof<F, C, D>> {
+    ) -> Result<Proof<F, C, D>>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         let mut builder = CircuitBuilder::<F, D>::new(config.clone());
         for _ in 0..num_dummy_gates {
             builder.add_gate(NoopGate, vec![]);
@@ -353,7 +362,11 @@ mod tests {
         print_timing: bool,
     ) -> Result<Proof<F, C, D>>
     where
-        InnerC::Hasher: AlgebraicHasher<F>,
+        InnerC::Hasher: AlgebraicHasher<F, InnerC::HCO>,
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+        [(); InnerC::HCO::WIDTH]:,
+        [(); InnerC::HCI::WIDTH]:,
     {
         let mut builder = CircuitBuilder::<F, D>::new(config.clone());
         let mut pw = PartialWitness::new();
@@ -405,7 +418,11 @@ mod tests {
         proof: &ProofWithPublicInputs<F, C, D>,
         vd: &VerifierOnlyCircuitData<C, D>,
         cd: &CommonCircuitData<F, D>,
-    ) -> Result<()> {
+    ) -> Result<()>
+    where
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+    {
         let proof_bytes = proof.to_bytes();
         info!("Proof length: {} bytes", proof_bytes.len());
         let proof_from_bytes = ProofWithPublicInputs::from_bytes(proof_bytes, cd)?;

plonky2/src/util/serialization.rs

@@ -14,6 +14,7 @@ use crate::fri::proof::{
     FriQueryStep,
 };
 use crate::hash::hash_types::RichField;
+use crate::hash::hashing::HashConfig;
 use crate::hash::merkle_proofs::MerkleProof;
 use crate::hash::merkle_tree::MerkleCap;
 use crate::plonk::circuit_data::CommonCircuitData;
@@ -119,10 +120,11 @@ pub trait Read {
 
     /// Reads a hash value from `self`.
     #[inline]
-    fn read_hash<F, H>(&mut self) -> IoResult<H::Hash>
+    fn read_hash<F, HC, H>(&mut self) -> IoResult<H::Hash>
     where
         F: RichField,
-        H: Hasher<F>,
+        HC: HashConfig,
+        H: Hasher<F, HC>,
     {
         let mut buf = vec![0; H::HASH_SIZE];
         self.read_exact(&mut buf)?;
@@ -131,15 +133,16 @@ pub trait Read {
 
     /// Reads a value of type [`MerkleCap`] from `self` with the given `cap_height`.
     #[inline]
-    fn read_merkle_cap<F, H>(&mut self, cap_height: usize) -> IoResult<MerkleCap<F, H>>
+    fn read_merkle_cap<F, HC, H>(&mut self, cap_height: usize) -> IoResult<MerkleCap<F, HC, H>>
     where
         F: RichField,
-        H: Hasher<F>,
+        HC: HashConfig,
+        H: Hasher<F, HC>,
     {
         let cap_length = 1 << cap_height;
         Ok(MerkleCap(
             (0..cap_length)
-                .map(|_| self.read_hash::<F, H>())
+                .map(|_| self.read_hash::<F, HC, H>())
                 .collect::<Result<Vec<_>, _>>()?,
         ))
     }
@@ -178,15 +181,16 @@ pub trait Read {
 
     /// Reads a value of type [`MerkleProof`] from `self`.
     #[inline]
-    fn read_merkle_proof<F, H>(&mut self) -> IoResult<MerkleProof<F, H>>
+    fn read_merkle_proof<F, HC, H>(&mut self) -> IoResult<MerkleProof<F, HC, H>>
     where
         F: RichField,
-        H: Hasher<F>,
+        HC: HashConfig,
+        H: Hasher<F, HC>,
     {
         let length = self.read_u8()?;
         Ok(MerkleProof {
             siblings: (0..length)
-                .map(|_| self.read_hash::<F, H>())
+                .map(|_| self.read_hash::<F, HC, H>())
                 .collect::<Result<_, _>>()?,
         })
     }
@@ -196,7 +200,7 @@ pub trait Read {
     fn read_fri_initial_proof<F, C, const D: usize>(
         &mut self,
         common_data: &CommonCircuitData<F, D>,
-    ) -> IoResult<FriInitialTreeProof<F, C::Hasher>>
+    ) -> IoResult<FriInitialTreeProof<F, C::HCO, C::Hasher>>
     where
         F: RichField + Extendable<D>,
         C: GenericConfig<D, F = F>,
@@ -235,7 +239,7 @@ pub trait Read {
         &mut self,
         arity: usize,
         compressed: bool,
-    ) -> IoResult<FriQueryStep<F, C::Hasher, D>>
+    ) -> IoResult<FriQueryStep<F, C::HCO, C::Hasher, D>>
     where
         F: RichField + Extendable<D>,
         C: GenericConfig<D, F = F>,
@@ -250,10 +254,11 @@ pub trait Read {
 
     /// Reads a vector of [`FriQueryRound`]s from `self` with `common_data`.
     #[inline]
+    #[allow(clippy::type_complexity)]
     fn read_fri_query_rounds<F, C, const D: usize>(
         &mut self,
         common_data: &CommonCircuitData<F, D>,
-    ) -> IoResult<Vec<FriQueryRound<F, C::Hasher, D>>>
+    ) -> IoResult<Vec<FriQueryRound<F, C::HCO, C::Hasher, D>>>
     where
         F: RichField + Extendable<D>,
         C: GenericConfig<D, F = F>,
@@ -281,7 +286,7 @@ pub trait Read {
     fn read_fri_proof<F, C, const D: usize>(
         &mut self,
         common_data: &CommonCircuitData<F, D>,
-    ) -> IoResult<FriProof<F, C::Hasher, D>>
+    ) -> IoResult<FriProof<F, C::HCO, C::Hasher, D>>
     where
         F: RichField + Extendable<D>,
         C: GenericConfig<D, F = F>,
@@ -352,7 +357,7 @@ pub trait Read {
     fn read_compressed_fri_query_rounds<F, C, const D: usize>(
         &mut self,
         common_data: &CommonCircuitData<F, D>,
-    ) -> IoResult<CompressedFriQueryRounds<F, C::Hasher, D>>
+    ) -> IoResult<CompressedFriQueryRounds<F, C::HCO, C::Hasher, D>>
     where
         F: RichField + Extendable<D>,
         C: GenericConfig<D, F = F>,
@@ -400,7 +405,7 @@ pub trait Read {
     fn read_compressed_fri_proof<F, C, const D: usize>(
         &mut self,
         common_data: &CommonCircuitData<F, D>,
-    ) -> IoResult<CompressedFriProof<F, C::Hasher, D>>
+    ) -> IoResult<CompressedFriProof<F, C::HCO, C::Hasher, D>>
     where
         F: RichField + Extendable<D>,
         C: GenericConfig<D, F = F>,
@@ -534,23 +539,25 @@ pub trait Write {
 
     /// Writes a hash `h` to `self`.
     #[inline]
-    fn write_hash<F, H>(&mut self, h: H::Hash) -> IoResult<()>
+    fn write_hash<F, HC, H>(&mut self, h: H::Hash) -> IoResult<()>
     where
         F: RichField,
-        H: Hasher<F>,
+        HC: HashConfig,
+        H: Hasher<F, HC>,
     {
         self.write_all(&h.to_bytes())
     }
 
     /// Writes `cap`, a value of type [`MerkleCap`], to `self`.
     #[inline]
-    fn write_merkle_cap<F, H>(&mut self, cap: &MerkleCap<F, H>) -> IoResult<()>
+    fn write_merkle_cap<F, HC, H>(&mut self, cap: &MerkleCap<F, HC, H>) -> IoResult<()>
     where
         F: RichField,
-        H: Hasher<F>,
+        HC: HashConfig,
+        H: Hasher<F, HC>,
     {
         for &a in &cap.0 {
-            self.write_hash::<F, H>(a)?;
+            self.write_hash::<F, HC, H>(a)?;
         }
         Ok(())
     }
@@ -572,10 +579,11 @@ pub trait Write {
 
     /// Writes a value `p` of type [`MerkleProof`] to `self.`
     #[inline]
-    fn write_merkle_proof<F, H>(&mut self, p: &MerkleProof<F, H>) -> IoResult<()>
+    fn write_merkle_proof<F, HC, H>(&mut self, p: &MerkleProof<F, HC, H>) -> IoResult<()>
     where
         F: RichField,
-        H: Hasher<F>,
+        HC: HashConfig,
+        H: Hasher<F, HC>,
     {
         let length = p.siblings.len();
         self.write_u8(
@@ -584,7 +592,7 @@ pub trait Write {
                 .expect("Merkle proof length must fit in u8."),
         )?;
         for &h in &p.siblings {
-            self.write_hash::<F, H>(h)?;
+            self.write_hash::<F, HC, H>(h)?;
         }
         Ok(())
     }
@@ -593,7 +601,7 @@ pub trait Write {
     #[inline]
     fn write_fri_initial_proof<F, C, const D: usize>(
         &mut self,
-        fitp: &FriInitialTreeProof<F, C::Hasher>,
+        fitp: &FriInitialTreeProof<F, C::HCO, C::Hasher>,
     ) -> IoResult<()>
     where
         F: RichField + Extendable<D>,
@@ -610,7 +618,7 @@ pub trait Write {
     #[inline]
     fn write_fri_query_step<F, C, const D: usize>(
         &mut self,
-        fqs: &FriQueryStep<F, C::Hasher, D>,
+        fqs: &FriQueryStep<F, C::HCO, C::Hasher, D>,
     ) -> IoResult<()>
     where
         F: RichField + Extendable<D>,
@@ -624,7 +632,7 @@ pub trait Write {
     #[inline]
     fn write_fri_query_rounds<F, C, const D: usize>(
         &mut self,
-        fqrs: &[FriQueryRound<F, C::Hasher, D>],
+        fqrs: &[FriQueryRound<F, C::HCO, C::Hasher, D>],
     ) -> IoResult<()>
     where
         F: RichField + Extendable<D>,
@@ -643,7 +651,7 @@ pub trait Write {
     #[inline]
     fn write_fri_proof<F, C, const D: usize>(
         &mut self,
-        fp: &FriProof<F, C::Hasher, D>,
+        fp: &FriProof<F, C::HCO, C::Hasher, D>,
     ) -> IoResult<()>
     where
         F: RichField + Extendable<D>,
@@ -693,7 +701,7 @@ pub trait Write {
     #[inline]
     fn write_compressed_fri_query_rounds<F, C, const D: usize>(
         &mut self,
-        cfqrs: &CompressedFriQueryRounds<F, C::Hasher, D>,
+        cfqrs: &CompressedFriQueryRounds<F, C::HCO, C::Hasher, D>,
     ) -> IoResult<()>
     where
         F: RichField + Extendable<D>,
@@ -721,7 +729,7 @@ pub trait Write {
     #[inline]
     fn write_compressed_fri_proof<F, C, const D: usize>(
         &mut self,
-        fp: &CompressedFriProof<F, C::Hasher, D>,
+        fp: &CompressedFriProof<F, C::HCO, C::Hasher, D>,
     ) -> IoResult<()>
     where
         F: RichField + Extendable<D>,

starky/src/fibonacci_stark.rs

@@ -127,12 +127,11 @@ mod tests {
     use plonky2::field::extension::Extendable;
     use plonky2::field::types::Field;
     use plonky2::hash::hash_types::RichField;
+    use plonky2::hash::hashing::HashConfig;
     use plonky2::iop::witness::PartialWitness;
     use plonky2::plonk::circuit_builder::CircuitBuilder;
     use plonky2::plonk::circuit_data::CircuitConfig;
-    use plonky2::plonk::config::{
+    use plonky2::plonk::config::{AlgebraicHasher, GenericConfig, PoseidonGoldilocksConfig};
-        AlgebraicHasher, GenericConfig, Hasher, PoseidonGoldilocksConfig,
-    };
     use plonky2::util::timing::TimingTree;
 
     use crate::config::StarkConfig;
@@ -236,10 +235,13 @@ mod tests {
         print_gate_counts: bool,
     ) -> Result<()>
     where
-        InnerC::Hasher: AlgebraicHasher<F>,
+        InnerC::Hasher: AlgebraicHasher<F, InnerC::HCO>,
         [(); S::COLUMNS]:,
         [(); S::PUBLIC_INPUTS]:,
-        [(); C::Hasher::HASH_SIZE]:,
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
+        [(); InnerC::HCO::WIDTH]:,
+        [(); InnerC::HCI::WIDTH]:,
     {
         let circuit_config = CircuitConfig::standard_recursion_config();
         let mut builder = CircuitBuilder::<F, D>::new(circuit_config);

starky/src/get_challenges.rs

@@ -5,6 +5,7 @@ use plonky2::field::polynomial::PolynomialCoeffs;
 use plonky2::fri::proof::{FriProof, FriProofTarget};
 use plonky2::gadgets::polynomial::PolynomialCoeffsExtTarget;
 use plonky2::hash::hash_types::{MerkleCapTarget, RichField};
+use plonky2::hash::hashing::HashConfig;
 use plonky2::hash::merkle_tree::MerkleCap;
 use plonky2::iop::challenger::{Challenger, RecursiveChallenger};
 use plonky2::iop::target::Target;
@@ -20,11 +21,11 @@ use crate::stark::Stark;
 
 fn get_challenges<F, C, S, const D: usize>(
     stark: &S,
-    trace_cap: &MerkleCap<F, C::Hasher>,
+    trace_cap: &MerkleCap<F, C::HCO, C::Hasher>,
-    permutation_zs_cap: Option<&MerkleCap<F, C::Hasher>>,
+    permutation_zs_cap: Option<&MerkleCap<F, C::HCO, C::Hasher>>,
-    quotient_polys_cap: &MerkleCap<F, C::Hasher>,
+    quotient_polys_cap: &MerkleCap<F, C::HCO, C::Hasher>,
     openings: &StarkOpeningSet<F, D>,
-    commit_phase_merkle_caps: &[MerkleCap<F, C::Hasher>],
+    commit_phase_merkle_caps: &[MerkleCap<F, C::HCO, C::Hasher>],
     final_poly: &PolynomialCoeffs<F::Extension>,
     pow_witness: F,
     config: &StarkConfig,
@@ -34,10 +35,12 @@ where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F>,
     S: Stark<F, D>,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     let num_challenges = config.num_challenges;
 
-    let mut challenger = Challenger::<F, C::Hasher>::new();
+    let mut challenger = Challenger::<F, C::HCO, C::Hasher>::new();
 
     challenger.observe_cap(trace_cap);
 
@@ -76,6 +79,8 @@ impl<F, C, const D: usize> StarkProofWithPublicInputs<F, C, D>
 where
     F: RichField + Extendable<D>,
     C: GenericConfig<D, F = F>,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     // TODO: Should be used later in compression?
     #![allow(dead_code)]
@@ -145,11 +150,13 @@ pub(crate) fn get_challenges_target<
     config: &StarkConfig,
 ) -> StarkProofChallengesTarget<D>
 where
-    C::Hasher: AlgebraicHasher<F>,
+    C::Hasher: AlgebraicHasher<F, C::HCO>,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     let num_challenges = config.num_challenges;
 
-    let mut challenger = RecursiveChallenger::<F, C::Hasher, D>::new(builder);
+    let mut challenger = RecursiveChallenger::<F, C::HCO, C::Hasher, D>::new(builder);
 
     challenger.observe_cap(trace_cap);
 
@@ -197,7 +204,9 @@ impl<const D: usize> StarkProofWithPublicInputsTarget<D> {
         config: &StarkConfig,
     ) -> StarkProofChallengesTarget<D>
     where
-        C::Hasher: AlgebraicHasher<F>,
+        C::Hasher: AlgebraicHasher<F, C::HCO>,
+        [(); C::HCO::WIDTH]:,
+        [(); C::HCI::WIDTH]:,
     {
         let StarkProofTarget {
             trace_cap,

starky/src/lib.rs

@@ -1,6 +1,7 @@
 #![allow(incomplete_features)]
 #![allow(clippy::too_many_arguments)]
 #![allow(clippy::type_complexity)]
+#![allow(clippy::upper_case_acronyms)]
 #![feature(generic_const_exprs)]
 #![cfg_attr(not(feature = "std"), no_std)]
 

starky/src/permutation.rs

@@ -10,6 +10,7 @@ use plonky2::field::packed::PackedField;
 use plonky2::field::polynomial::PolynomialValues;
 use plonky2::field::types::Field;
 use plonky2::hash::hash_types::RichField;
+use plonky2::hash::hashing::HashConfig;
 use plonky2::iop::challenger::{Challenger, RecursiveChallenger};
 use plonky2::iop::ext_target::ExtensionTarget;
 use plonky2::iop::target::Target;
@@ -149,29 +150,38 @@ fn poly_product_elementwise<F: Field>(
     product
 }
 
-fn get_permutation_challenge<F: RichField, H: Hasher<F>>(
+fn get_permutation_challenge<F: RichField, HC: HashConfig, H: Hasher<F, HC>>(
-    challenger: &mut Challenger<F, H>,
+    challenger: &mut Challenger<F, HC, H>,
-) -> PermutationChallenge<F> {
+) -> PermutationChallenge<F>
+where
+    [(); HC::WIDTH]:,
+{
     let beta = challenger.get_challenge();
     let gamma = challenger.get_challenge();
     PermutationChallenge { beta, gamma }
 }
 
-fn get_permutation_challenge_set<F: RichField, H: Hasher<F>>(
+fn get_permutation_challenge_set<F: RichField, HC: HashConfig, H: Hasher<F, HC>>(
-    challenger: &mut Challenger<F, H>,
+    challenger: &mut Challenger<F, HC, H>,
     num_challenges: usize,
-) -> PermutationChallengeSet<F> {
+) -> PermutationChallengeSet<F>
+where
+    [(); HC::WIDTH]:,
+{
     let challenges = (0..num_challenges)
         .map(|_| get_permutation_challenge(challenger))
         .collect();
     PermutationChallengeSet { challenges }
 }
 
-pub(crate) fn get_n_permutation_challenge_sets<F: RichField, H: Hasher<F>>(
+pub(crate) fn get_n_permutation_challenge_sets<F: RichField, HC: HashConfig, H: Hasher<F, HC>>(
-    challenger: &mut Challenger<F, H>,
+    challenger: &mut Challenger<F, HC, H>,
     num_challenges: usize,
     num_sets: usize,
-) -> Vec<PermutationChallengeSet<F>> {
+) -> Vec<PermutationChallengeSet<F>>
+where
+    [(); HC::WIDTH]:,
+{
     (0..num_sets)
         .map(|_| get_permutation_challenge_set(challenger, num_challenges))
         .collect()
@@ -179,12 +189,16 @@ pub(crate) fn get_n_permutation_challenge_sets<F: RichField, H: Hasher<F>>(
 
 fn get_permutation_challenge_target<
     F: RichField + Extendable<D>,
-    H: AlgebraicHasher<F>,
+    HC: HashConfig,
+    H: AlgebraicHasher<F, HC>,
     const D: usize,
 >(
     builder: &mut CircuitBuilder<F, D>,
-    challenger: &mut RecursiveChallenger<F, H, D>,
+    challenger: &mut RecursiveChallenger<F, HC, H, D>,
-) -> PermutationChallenge<Target> {
+) -> PermutationChallenge<Target>
+where
+    [(); HC::WIDTH]:,
+{
     let beta = challenger.get_challenge(builder);
     let gamma = challenger.get_challenge(builder);
     PermutationChallenge { beta, gamma }
@@ -192,13 +206,17 @@ fn get_permutation_challenge_target<
 
 fn get_permutation_challenge_set_target<
     F: RichField + Extendable<D>,
-    H: AlgebraicHasher<F>,
+    HC: HashConfig,
+    H: AlgebraicHasher<F, HC>,
     const D: usize,
 >(
     builder: &mut CircuitBuilder<F, D>,
-    challenger: &mut RecursiveChallenger<F, H, D>,
+    challenger: &mut RecursiveChallenger<F, HC, H, D>,
     num_challenges: usize,
-) -> PermutationChallengeSet<Target> {
+) -> PermutationChallengeSet<Target>
+where
+    [(); HC::WIDTH]:,
+{
     let challenges = (0..num_challenges)
         .map(|_| get_permutation_challenge_target(builder, challenger))
         .collect();
@@ -207,14 +225,18 @@ fn get_permutation_challenge_set_target<
 
 pub(crate) fn get_n_permutation_challenge_sets_target<
     F: RichField + Extendable<D>,
-    H: AlgebraicHasher<F>,
+    HC: HashConfig,
+    H: AlgebraicHasher<F, HC>,
     const D: usize,
 >(
     builder: &mut CircuitBuilder<F, D>,
-    challenger: &mut RecursiveChallenger<F, H, D>,
+    challenger: &mut RecursiveChallenger<F, HC, H, D>,
     num_challenges: usize,
     num_sets: usize,
-) -> Vec<PermutationChallengeSet<Target>> {
+) -> Vec<PermutationChallengeSet<Target>>
+where
+    [(); HC::WIDTH]:,
+{
     (0..num_sets)
         .map(|_| get_permutation_challenge_set_target(builder, challenger, num_challenges))
         .collect()

starky/src/proof.rs

@@ -23,15 +23,15 @@ use crate::permutation::PermutationChallengeSet;
 #[derive(Debug, Clone)]
 pub struct StarkProof<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize> {
     /// Merkle cap of LDEs of trace values.
-    pub trace_cap: MerkleCap<F, C::Hasher>,
+    pub trace_cap: MerkleCap<F, C::HCO, C::Hasher>,
     /// Merkle cap of LDEs of permutation Z values.
-    pub permutation_zs_cap: Option<MerkleCap<F, C::Hasher>>,
+    pub permutation_zs_cap: Option<MerkleCap<F, C::HCO, C::Hasher>>,
     /// Merkle cap of LDEs of trace values.
-    pub quotient_polys_cap: MerkleCap<F, C::Hasher>,
+    pub quotient_polys_cap: MerkleCap<F, C::HCO, C::Hasher>,
     /// Purported values of each polynomial at the challenge point.
     pub openings: StarkOpeningSet<F, D>,
     /// A batch FRI argument for all openings.
-    pub opening_proof: FriProof<F, C::Hasher, D>,
+    pub opening_proof: FriProof<F, C::HCO, C::Hasher, D>,
 }
 
 impl<F: RichField + Extendable<D>, C: GenericConfig<D, F = F>, const D: usize> StarkProof<F, C, D> {
@@ -88,11 +88,11 @@ pub struct CompressedStarkProof<
     const D: usize,
 > {
     /// Merkle cap of LDEs of trace values.
-    pub trace_cap: MerkleCap<F, C::Hasher>,
+    pub trace_cap: MerkleCap<F, C::HCO, C::Hasher>,
     /// Purported values of each polynomial at the challenge point.
     pub openings: StarkOpeningSet<F, D>,
     /// A batch FRI argument for all openings.
-    pub opening_proof: CompressedFriProof<F, C::Hasher, D>,
+    pub opening_proof: CompressedFriProof<F, C::HCO, C::Hasher, D>,
 }
 
 pub struct CompressedStarkProofWithPublicInputs<

starky/src/prover.rs

@@ -11,8 +11,9 @@ use plonky2::field::types::Field;
 use plonky2::field::zero_poly_coset::ZeroPolyOnCoset;
 use plonky2::fri::oracle::PolynomialBatch;
 use plonky2::hash::hash_types::RichField;
+use plonky2::hash::hashing::HashConfig;
 use plonky2::iop::challenger::Challenger;
-use plonky2::plonk::config::{GenericConfig, Hasher};
+use plonky2::plonk::config::GenericConfig;
 use plonky2::timed;
 use plonky2::util::timing::TimingTree;
 use plonky2::util::{log2_ceil, log2_strict, transpose};
@@ -42,7 +43,8 @@ where
     S: Stark<F, D>,
     [(); S::COLUMNS]:,
     [(); S::PUBLIC_INPUTS]:,
-    [(); C::Hasher::HASH_SIZE]:,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     let degree = trace_poly_values[0].len();
     let degree_bits = log2_strict(degree);

starky/src/recursive_verifier.rs

@@ -7,6 +7,7 @@ use plonky2::field::extension::Extendable;
 use plonky2::field::types::Field;
 use plonky2::fri::witness_util::set_fri_proof_target;
 use plonky2::hash::hash_types::RichField;
+use plonky2::hash::hashing::HashConfig;
 use plonky2::iop::ext_target::ExtensionTarget;
 use plonky2::iop::witness::Witness;
 use plonky2::plonk::circuit_builder::CircuitBuilder;
@@ -36,9 +37,11 @@ pub fn verify_stark_proof_circuit<
     proof_with_pis: StarkProofWithPublicInputsTarget<D>,
     inner_config: &StarkConfig,
 ) where
-    C::Hasher: AlgebraicHasher<F>,
+    C::Hasher: AlgebraicHasher<F, C::HCO>,
     [(); S::COLUMNS]:,
     [(); S::PUBLIC_INPUTS]:,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     assert_eq!(proof_with_pis.public_inputs.len(), S::PUBLIC_INPUTS);
     let degree_bits = proof_with_pis.proof.recover_degree_bits(inner_config);
@@ -72,9 +75,10 @@ fn verify_stark_proof_with_challenges_circuit<
     inner_config: &StarkConfig,
     degree_bits: usize,
 ) where
-    C::Hasher: AlgebraicHasher<F>,
+    C::Hasher: AlgebraicHasher<F, C::HCO>,
     [(); S::COLUMNS]:,
     [(); S::PUBLIC_INPUTS]:,
+    [(); C::HCO::WIDTH]:,
 {
     check_permutation_options(&stark, &proof_with_pis, &challenges).unwrap();
     let one = builder.one_extension();
@@ -265,7 +269,7 @@ pub fn set_stark_proof_with_pis_target<F, C: GenericConfig<D, F = F>, W, const D
     stark_proof_with_pis: &StarkProofWithPublicInputs<F, C, D>,
 ) where
     F: RichField + Extendable<D>,
-    C::Hasher: AlgebraicHasher<F>,
+    C::Hasher: AlgebraicHasher<F, C::HCO>,
     W: Witness<F>,
 {
     let StarkProofWithPublicInputs {
@@ -291,7 +295,7 @@ pub fn set_stark_proof_target<F, C: GenericConfig<D, F = F>, W, const D: usize>(
     proof: &StarkProof<F, C, D>,
 ) where
     F: RichField + Extendable<D>,
-    C::Hasher: AlgebraicHasher<F>,
+    C::Hasher: AlgebraicHasher<F, C::HCO>,
     W: Witness<F>,
 {
     witness.set_cap_target(&proof_target.trace_cap, &proof.trace_cap);

starky/src/stark_testing.rs

@@ -6,10 +6,11 @@ use plonky2::field::extension::{Extendable, FieldExtension};
 use plonky2::field::polynomial::{PolynomialCoeffs, PolynomialValues};
 use plonky2::field::types::{Field, Sample};
 use plonky2::hash::hash_types::RichField;
+use plonky2::hash::hashing::HashConfig;
 use plonky2::iop::witness::{PartialWitness, WitnessWrite};
 use plonky2::plonk::circuit_builder::CircuitBuilder;
 use plonky2::plonk::circuit_data::CircuitConfig;
-use plonky2::plonk::config::{GenericConfig, Hasher};
+use plonky2::plonk::config::GenericConfig;
 use plonky2::util::{log2_ceil, log2_strict, transpose};
 
 use crate::constraint_consumer::{ConstraintConsumer, RecursiveConstraintConsumer};
@@ -89,7 +90,8 @@ pub fn test_stark_circuit_constraints<
 where
     [(); S::COLUMNS]:,
     [(); S::PUBLIC_INPUTS]:,
-    [(); C::Hasher::HASH_SIZE]:,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     // Compute native constraint evaluation on random values.
     let vars = StarkEvaluationVars {

starky/src/verifier.rs

@@ -7,7 +7,8 @@ use plonky2::field::extension::{Extendable, FieldExtension};
 use plonky2::field::types::Field;
 use plonky2::fri::verifier::verify_fri_proof;
 use plonky2::hash::hash_types::RichField;
-use plonky2::plonk::config::{GenericConfig, Hasher};
+use plonky2::hash::hashing::HashConfig;
+use plonky2::plonk::config::GenericConfig;
 use plonky2::plonk::plonk_common::reduce_with_powers;
 
 use crate::config::StarkConfig;
@@ -31,7 +32,8 @@ pub fn verify_stark_proof<
 where
     [(); S::COLUMNS]:,
     [(); S::PUBLIC_INPUTS]:,
-    [(); C::Hasher::HASH_SIZE]:,
+    [(); C::HCO::WIDTH]:,
+    [(); C::HCI::WIDTH]:,
 {
     ensure!(proof_with_pis.public_inputs.len() == S::PUBLIC_INPUTS);
     let degree_bits = proof_with_pis.proof.recover_degree_bits(config);
@@ -54,7 +56,7 @@ pub(crate) fn verify_stark_proof_with_challenges<
 where
     [(); S::COLUMNS]:,
     [(); S::PUBLIC_INPUTS]:,
-    [(); C::Hasher::HASH_SIZE]:,
+    [(); C::HCO::WIDTH]:,
 {
     validate_proof_shape(&stark, &proof_with_pis, config)?;
     check_permutation_options(&stark, &proof_with_pis, &challenges)?;
@@ -156,7 +158,6 @@ where
     C: GenericConfig<D, F = F>,
     S: Stark<F, D>,
     [(); S::COLUMNS]:,
-    [(); C::Hasher::HASH_SIZE]:,
 {
     let StarkProofWithPublicInputs {
         proof,