Merge pull request #27 from logos-co/goas/collision-resistant-nullifier

goas: make nullifier collision resistant

goas/atomic_asset_transfer/Cargo.toml

@@ -8,4 +8,4 @@ opt-level = 3
 
 [profile.release]
 debug = 1
-lto = true
+lto = true

goas/atomic_asset_transfer/common/Cargo.toml

@@ -9,3 +9,7 @@ cl = { path = "../../cl/cl" }
 ledger_proof_statements = { path = "../../cl/ledger_proof_statements" }
 once_cell = "1"
 sha2 = "0.10"
+curve25519-dalek = { version = "4.1", features = ["serde", "digest", "rand_core"] }
+ed25519-dalek = { version = "2.1.1", features = ["rand_core"] }
+rand_core = "0.6.0"
+serde_arrays = "0.1.0"

goas/atomic_asset_transfer/common/src/lib.rs

@@ -1,5 +1,10 @@
-use cl::{balance::Unit, merkle, PartialTxInputWitness};
+use cl::{balance::Unit, merkle, NoteCommitment};
+use ed25519_dalek::{
+    ed25519::{signature::SignerMut, SignatureBytes},
+    Signature, SigningKey, VerifyingKey, PUBLIC_KEY_LENGTH,
+};
 use once_cell::sync::Lazy;
+use rand_core::CryptoRngCore;
 use serde::{Deserialize, Serialize};
 use sha2::{Digest, Sha256};
 use std::collections::BTreeMap;
@@ -13,11 +18,15 @@ pub const MAX_EVENTS: usize = 1 << 8;
 #[derive(Debug, PartialEq, Eq, Clone, Copy, Serialize, Deserialize)]
 pub struct StateCommitment(pub [u8; 32]);
 
-pub type AccountId = u32;
+pub type AccountId = [u8; PUBLIC_KEY_LENGTH];
 
 // PLACEHOLDER: this is probably going to be NMO?
 pub static ZONE_CL_FUNDS_UNIT: Lazy<Unit> = Lazy::new(|| cl::note::unit_point("NMO"));
 
+pub fn new_account(mut rng: impl CryptoRngCore) -> SigningKey {
+    SigningKey::generate(&mut rng)
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
 pub struct ZoneMetadata {
     pub zone_vk: [u8; 32],
@@ -40,7 +49,6 @@ pub struct StateWitness {
     pub balances: BTreeMap<AccountId, u64>,
     pub included_txs: Vec<Tx>,
     pub zone_metadata: ZoneMetadata,
-    pub nonce: [u8; 32],
 }
 
 impl StateWitness {
@@ -50,7 +58,6 @@ impl StateWitness {
 
     pub fn state_roots(&self) -> StateRoots {
         StateRoots {
-            nonce: self.nonce,
             tx_root: self.included_txs_root(),
             zone_id: self.zone_metadata.id(),
             balance_root: self.balances_root(),
@@ -95,7 +102,7 @@ impl StateWitness {
     }
 
     pub fn included_tx_witness(&self, idx: usize) -> IncludedTxWitness {
-        let tx = self.included_txs.get(idx).unwrap().clone();
+        let tx = *self.included_txs.get(idx).unwrap();
         let path = merkle::path(self.included_tx_merkle_leaves(), idx);
         IncludedTxWitness { tx, path }
     }
@@ -103,7 +110,7 @@ impl StateWitness {
     pub fn balances_root(&self) -> [u8; 32] {
         let balance_bytes = Vec::from_iter(self.balances.iter().map(|(owner, balance)| {
             let mut bytes: Vec<u8> = vec![];
-            bytes.extend(owner.to_le_bytes());
+            bytes.extend(owner);
             bytes.extend(balance.to_le_bytes());
             bytes
         }));
@@ -115,19 +122,6 @@ impl StateWitness {
         self.balances.values().sum()
     }
 
-    pub fn evolve_nonce(self) -> Self {
-        let updated_nonce = {
-            let mut hasher = Sha256::new();
-            hasher.update(self.nonce);
-            hasher.update(b"NOMOS_ZONE_NONCE_EVOLVE");
-            hasher.finalize().into()
-        };
-        Self {
-            nonce: updated_nonce,
-            ..self
-        }
-    }
-
     fn included_tx_merkle_leaves(&self) -> [[u8; 32]; MAX_TXS] {
         let tx_bytes = self
             .included_txs
@@ -151,10 +145,10 @@ pub struct Withdraw {
 }
 
 impl Withdraw {
-    pub fn to_bytes(&self) -> [u8; 12] {
+    pub fn to_bytes(&self) -> [u8; 40] {
-        let mut bytes = [0; 12];
+        let mut bytes = [0; 40];
-        bytes[0..4].copy_from_slice(&self.from.to_le_bytes());
+        bytes[0..PUBLIC_KEY_LENGTH].copy_from_slice(&self.from);
-        bytes[4..12].copy_from_slice(&self.amount.to_le_bytes());
+        bytes[PUBLIC_KEY_LENGTH..PUBLIC_KEY_LENGTH + 8].copy_from_slice(&self.amount.to_le_bytes());
         bytes
     }
 }
@@ -167,31 +161,58 @@ pub struct Deposit {
 }
 
 impl Deposit {
-    pub fn to_bytes(&self) -> [u8; 12] {
+    pub fn to_bytes(&self) -> [u8; 40] {
-        let mut bytes = [0; 12];
+        let mut bytes = [0; 40];
-        bytes[0..4].copy_from_slice(&self.to.to_le_bytes());
+        bytes[0..PUBLIC_KEY_LENGTH].copy_from_slice(&self.to);
-        bytes[4..12].copy_from_slice(&self.amount.to_le_bytes());
+        bytes[PUBLIC_KEY_LENGTH..PUBLIC_KEY_LENGTH + 8].copy_from_slice(&self.amount.to_le_bytes());
         bytes
     }
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+pub struct SignedBoundTx {
+    pub bound_tx: BoundTx,
+    #[serde(with = "serde_arrays")]
+    pub sig: SignatureBytes,
+}
+
+impl SignedBoundTx {
+    pub fn sign(bound_tx: BoundTx, signing_key: &mut SigningKey) -> Self {
+        let msg = bound_tx.to_bytes();
+        let sig = signing_key.sign(&msg).to_bytes();
+
+        Self { bound_tx, sig }
+    }
+
+    pub fn verify_and_unwrap(&self) -> BoundTx {
+        let msg = self.bound_tx.to_bytes();
+
+        let sig = Signature::from_bytes(&self.sig);
+        let vk = self.bound_tx.tx.verifying_key();
+        vk.verify_strict(&msg, &sig).expect("Invalid tx signature");
+
+        self.bound_tx
+    }
+}
+
 /// A Tx that is executed in the zone if and only if the bind is
 /// present is the same partial transaction
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
 pub struct BoundTx {
     pub tx: Tx,
-    pub bind: PartialTxInputWitness,
+    pub bind: NoteCommitment,
 }
 
 impl BoundTx {
     pub fn to_bytes(&self) -> Vec<u8> {
-        let mut bytes = self.tx.to_bytes();
+        let mut bytes = Vec::new();
-        bytes.extend(self.bind.input.commit().to_bytes());
+        bytes.extend(self.tx.to_bytes());
+        bytes.extend(self.bind.as_bytes());
         bytes
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
 pub enum Tx {
     Withdraw(Withdraw),
     Deposit(Deposit),
@@ -204,6 +225,13 @@ impl Tx {
             Tx::Deposit(deposit) => deposit.to_bytes().to_vec(),
         }
     }
+
+    pub fn verifying_key(&self) -> VerifyingKey {
+        match self {
+            Tx::Withdraw(w) => VerifyingKey::from_bytes(&w.from).unwrap(),
+            Tx::Deposit(d) => VerifyingKey::from_bytes(&d.to).unwrap(),
+        }
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
@@ -221,25 +249,19 @@ impl IncludedTxWitness {
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct StateRoots {
-    pub nonce: [u8; 32],
     pub tx_root: [u8; 32],
     pub zone_id: [u8; 32],
     pub balance_root: [u8; 32],
 }
 
 impl StateRoots {
-    /// Merkle tree over:
+    /// Merkle tree over: [txs, zoneid, balances]
-    ///                  root
-    ///              /        \
-    ///            io          state
-    ///          /   \        /     \
-    ///      nonce   txs   zoneid  balances
     pub fn commit(&self) -> StateCommitment {
-        StateCommitment(cl::merkle::root([
+        let leaves = cl::merkle::padded_leaves::<4>(&[
-            self.nonce,
+            self.tx_root.to_vec(),
-            self.tx_root,
+            self.zone_id.to_vec(),
-            self.zone_id,
+            self.balance_root.to_vec(),
-            self.balance_root,
+        ]);
-        ]))
+        StateCommitment(cl::merkle::root(leaves))
     }
 }

goas/atomic_asset_transfer/executor/src/lib.rs

@@ -1,6 +1,6 @@
 use std::collections::BTreeMap;
 
-use common::{BoundTx, StateWitness, Tx, ZoneMetadata};
+use common::{AccountId, SignedBoundTx, StateWitness, Tx, ZoneMetadata};
 use goas_proof_statements::{
     user_note::UserAtomicTransfer, zone_funds::SpendFundsPrivate, zone_state::ZoneStatePrivate,
 };
@@ -16,14 +16,13 @@ pub struct ZoneNotes {
 impl ZoneNotes {
     pub fn new_with_balances(
         zone_name: &str,
-        balances: BTreeMap<u32, u64>,
+        balances: BTreeMap<AccountId, u64>,
         mut rng: impl CryptoRngCore,
     ) -> Self {
         let state = StateWitness {
             balances,
             included_txs: vec![],
             zone_metadata: zone_metadata(zone_name),
-            nonce: [0; 32],
         };
         let state_note = zone_state_utxo(&state, &mut rng);
         let fund_note = zone_fund_utxo(state.total_balance(), state.zone_metadata, &mut rng);
@@ -46,7 +45,6 @@ impl ZoneNotes {
         for tx in txs {
             self.state = self.state.apply(tx);
         }
-        self.state = self.state.evolve_nonce();
 
         let state_in = self.state_input_witness();
         self.state_note = cl::OutputWitness::public(
@@ -54,7 +52,7 @@ impl ZoneNotes {
                 state: self.state.commit().0,
                 ..state_in.note
             },
-            state_in.evolved_nonce(),
+            state_in.evolved_nonce(b"STATE_NONCE"),
         );
 
         let fund_in = self.fund_input_witness();
@@ -63,7 +61,7 @@ impl ZoneNotes {
                 value: self.state.total_balance(),
                 ..fund_in.note
             },
-            cl::NullifierNonce::from_bytes(self.state.nonce),
+            state_in.evolved_nonce(b"FUND_NONCE"),
         );
         self
     }
@@ -123,7 +121,7 @@ pub fn zone_metadata(zone_mnemonic: &str) -> ZoneMetadata {
 
 pub fn prove_zone_stf(
     state: StateWitness,
-    inputs: Vec<BoundTx>,
+    inputs: Vec<(SignedBoundTx, cl::PartialTxInputWitness)>,
     zone_in: cl::PartialTxInputWitness,
     zone_out: cl::PartialTxOutputWitness,
     funds_out: cl::PartialTxOutputWitness,

goas/atomic_asset_transfer/executor/tests/atomic_transfer.rs

@@ -1,7 +1,7 @@
 use std::collections::BTreeMap;
 
 use cl::{BundleWitness, NoteWitness, NullifierNonce};
-use common::{BoundTx, Deposit, Tx, Withdraw};
+use common::{new_account, BoundTx, Deposit, SignedBoundTx, Tx, Withdraw};
 use executor::ZoneNotes;
 use goas_proof_statements::user_note::{UserAtomicTransfer, UserIntent};
 
@@ -9,10 +9,11 @@ use goas_proof_statements::user_note::{UserAtomicTransfer, UserIntent};
 fn test_atomic_transfer() {
     let mut rng = rand::thread_rng();
 
-    let alice = 42;
+    let mut alice = new_account(&mut rng);
+    let alice_vk = alice.verifying_key().to_bytes();
 
     let zone_a_start =
-        ZoneNotes::new_with_balances("ZONE_A", BTreeMap::from_iter([(alice, 100)]), &mut rng);
+        ZoneNotes::new_with_balances("ZONE_A", BTreeMap::from_iter([(alice_vk, 100)]), &mut rng);
 
     let zone_b_start = ZoneNotes::new_with_balances("ZONE_B", BTreeMap::from_iter([]), &mut rng);
 
@@ -20,11 +21,11 @@ fn test_atomic_transfer() {
         zone_a_meta: zone_a_start.state.zone_metadata,
         zone_b_meta: zone_b_start.state.zone_metadata,
         withdraw: Withdraw {
-            from: alice,
+            from: alice_vk,
             amount: 75,
         },
         deposit: Deposit {
-            to: alice,
+            to: alice_vk,
             amount: 75,
         },
     };
@@ -69,6 +70,21 @@ fn test_atomic_transfer() {
         ],
     };
 
+    let signed_withdraw = SignedBoundTx::sign(
+        BoundTx {
+            tx: Tx::Withdraw(alice_intent.withdraw),
+            bind: alice_intent_in.note_commitment(),
+        },
+        &mut alice,
+    );
+    let signed_deposit = SignedBoundTx::sign(
+        BoundTx {
+            tx: Tx::Deposit(alice_intent.deposit),
+            bind: alice_intent_in.note_commitment(),
+        },
+        &mut alice,
+    );
+
     let death_proofs = BTreeMap::from_iter([
         (
             alice_intent_in.nullifier(),
@@ -87,13 +103,10 @@ fn test_atomic_transfer() {
             zone_a_start.state_input_witness().nullifier(),
             executor::prove_zone_stf(
                 zone_a_start.state.clone(),
-                vec![BoundTx {
+                vec![(signed_withdraw, atomic_transfer_ptx.input_witness(0))], // withdraw bound to input intent note
-                    tx: Tx::Withdraw(alice_intent.withdraw),
+                atomic_transfer_ptx.input_witness(1),                          // input state note
-                    bind: atomic_transfer_ptx.input_witness(0), // input intent note
+                atomic_transfer_ptx.output_witness(0),                         // output state note
-                }],
+                atomic_transfer_ptx.output_witness(1),                         // output funds note
-                atomic_transfer_ptx.input_witness(1), // input state note
-                atomic_transfer_ptx.output_witness(0), // output state note
-                atomic_transfer_ptx.output_witness(1), // output funds note
             ),
         ),
         (
@@ -108,13 +121,10 @@ fn test_atomic_transfer() {
             zone_b_start.state_input_witness().nullifier(),
             executor::prove_zone_stf(
                 zone_b_start.state.clone(),
-                vec![BoundTx {
+                vec![(signed_deposit, atomic_transfer_ptx.input_witness(0))], // deposit bound to input intent note
-                    tx: Tx::Deposit(alice_intent.deposit),
+                atomic_transfer_ptx.input_witness(3),                         // input state note
-                    bind: atomic_transfer_ptx.input_witness(0), // input intent note
+                atomic_transfer_ptx.output_witness(2),                        // output state note
-                }],
+                atomic_transfer_ptx.output_witness(3),                        // output funds note
-                atomic_transfer_ptx.input_witness(3), // input state note
-                atomic_transfer_ptx.output_witness(2), // output state note
-                atomic_transfer_ptx.output_witness(3), // output funds note
             ),
         ),
         (

goas/atomic_asset_transfer/executor/tests/deposit_ptx.rs

@@ -1,7 +1,7 @@
 use std::collections::BTreeMap;
 
 use cl::{NoteWitness, NullifierSecret};
-use common::{BoundTx, StateWitness, Tx, ZONE_CL_FUNDS_UNIT};
+use common::{new_account, BoundTx, SignedBoundTx, StateWitness, Tx, ZONE_CL_FUNDS_UNIT};
 use executor::ZoneNotes;
 use ledger::death_constraint::DeathProof;
 
@@ -9,13 +9,14 @@ use ledger::death_constraint::DeathProof;
 fn test_deposit() {
     let mut rng = rand::thread_rng();
 
-    let alice = 42;
+    let mut alice = new_account(&mut rng);
-    let alice_sk = NullifierSecret::random(&mut rng);
+    let alice_vk = alice.verifying_key().to_bytes();
+    let alice_cl_sk = NullifierSecret::random(&mut rng);
 
     let zone_start = ZoneNotes::new_with_balances("ZONE", BTreeMap::new(), &mut rng);
 
     let deposit = common::Deposit {
-        to: alice,
+        to: alice_vk,
         amount: 78,
     };
 
@@ -28,10 +29,10 @@ fn test_deposit() {
                 *ZONE_CL_FUNDS_UNIT,
                 DeathProof::nop_constraint(), // alice should demand a tx inclusion proof for the deposit
             ),
-            alice_sk.commit(),
+            alice_cl_sk.commit(),
             &mut rng,
         ),
-        alice_sk,
+        alice_cl_sk,
         &mut rng,
     );
 
@@ -40,16 +41,21 @@ fn test_deposit() {
         outputs: vec![zone_end.state_note, zone_end.fund_note],
     };
 
+    let signed_deposit = SignedBoundTx::sign(
+        BoundTx {
+            tx: Tx::Deposit(deposit),
+            bind: alice_deposit.note_commitment(),
+        },
+        &mut alice,
+    );
+
     let death_proofs = BTreeMap::from_iter([
         (
             zone_start.state_input_witness().nullifier(),
             executor::prove_zone_stf(
                 zone_start.state.clone(),
-                vec![BoundTx {
+                vec![(signed_deposit, deposit_ptx.input_witness(1))], // bind it to the deposit note)],
-                    tx: Tx::Deposit(deposit),
+                deposit_ptx.input_witness(0),                         // input state note (input #0)
-                    bind: deposit_ptx.input_witness(1), // bind it to the deposit note
-                }],
-                deposit_ptx.input_witness(0), // input state note (input #0)
                 deposit_ptx.output_witness(0), // output state note (output #0)
                 deposit_ptx.output_witness(1), // output funds note (output #1)
             ),
@@ -78,10 +84,9 @@ fn test_deposit() {
     assert_eq!(
         zone_end.state_note.note.state,
         StateWitness {
-            balances: BTreeMap::from_iter([(alice, 78)]),
+            balances: BTreeMap::from_iter([(alice_vk, 78)]),
             included_txs: vec![Tx::Deposit(deposit)],
             zone_metadata: zone_start.state.zone_metadata,
-            nonce: zone_start.state.evolve_nonce().nonce,
         }
         .commit()
         .0

goas/atomic_asset_transfer/executor/tests/withdraw_ptx.rs

@@ -1,7 +1,7 @@
 use std::collections::BTreeMap;
 
 use cl::{NoteWitness, NullifierSecret};
-use common::{BoundTx, StateWitness, Tx, ZONE_CL_FUNDS_UNIT};
+use common::{new_account, BoundTx, SignedBoundTx, StateWitness, Tx, ZONE_CL_FUNDS_UNIT};
 use executor::ZoneNotes;
 use ledger::death_constraint::DeathProof;
 
@@ -9,24 +9,25 @@ use ledger::death_constraint::DeathProof;
 fn test_withdrawal() {
     let mut rng = rand::thread_rng();
 
-    let alice = 42;
+    let mut alice = new_account(&mut rng);
-    let alice_sk = NullifierSecret::random(&mut rng);
+    let alice_vk = alice.verifying_key().to_bytes();
+    let alice_cl_sk = NullifierSecret::random(&mut rng);
 
     let zone_start =
-        ZoneNotes::new_with_balances("ZONE", BTreeMap::from_iter([(alice, 100)]), &mut rng);
+        ZoneNotes::new_with_balances("ZONE", BTreeMap::from_iter([(alice_vk, 100)]), &mut rng);
 
     let alice_intent = cl::InputWitness::random(
         cl::OutputWitness::random(
             NoteWitness::stateless(1, *ZONE_CL_FUNDS_UNIT, DeathProof::nop_constraint()), // TODO, intent should be in the death constraint
-            alice_sk.commit(),
+            alice_cl_sk.commit(),
             &mut rng,
         ),
-        alice_sk,
+        alice_cl_sk,
         &mut rng,
     );
 
     let withdraw = common::Withdraw {
-        from: alice,
+        from: alice_vk,
         amount: 78,
     };
 
@@ -38,7 +39,7 @@ fn test_withdrawal() {
             *ZONE_CL_FUNDS_UNIT,
             DeathProof::nop_constraint(),
         ),
-        alice_sk.commit(),
+        alice_cl_sk.commit(),
         &mut rng,
     );
 
@@ -51,15 +52,20 @@ fn test_withdrawal() {
         outputs: vec![zone_end.state_note, zone_end.fund_note, alice_withdrawal],
     };
 
+    let signed_withdraw = SignedBoundTx::sign(
+        BoundTx {
+            tx: Tx::Withdraw(withdraw),
+            bind: alice_intent.note_commitment(),
+        },
+        &mut alice,
+    );
+
     let death_proofs = BTreeMap::from_iter([
         (
             zone_start.state_input_witness().nullifier(),
             executor::prove_zone_stf(
                 zone_start.state.clone(),
-                vec![BoundTx {
+                vec![(signed_withdraw, withdraw_ptx.input_witness(2))],
-                    tx: Tx::Withdraw(withdraw),
-                    bind: withdraw_ptx.input_witness(2),
-                }],
                 withdraw_ptx.input_witness(0), // input state note (input #0)
                 withdraw_ptx.output_witness(0), // output state note (output #0)
                 withdraw_ptx.output_witness(1), // output funds note (output #1)
@@ -98,10 +104,9 @@ fn test_withdrawal() {
     assert_eq!(
         zone_end.state_note.note.state,
         StateWitness {
-            balances: BTreeMap::from_iter([(alice, 22)]),
+            balances: BTreeMap::from_iter([(alice_vk, 22)]),
             included_txs: vec![Tx::Withdraw(withdraw)],
             zone_metadata: zone_start.state.zone_metadata,
-            nonce: zone_start.state.evolve_nonce().nonce,
         }
         .commit()
         .0

goas/atomic_asset_transfer/proof_statements/src/zone_state.rs

@@ -1,10 +1,10 @@
-use common::{BoundTx, StateWitness};
+use common::{SignedBoundTx, StateWitness};
 use serde::{Deserialize, Serialize};
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct ZoneStatePrivate {
     pub state: StateWitness,
-    pub inputs: Vec<BoundTx>,
+    pub inputs: Vec<(SignedBoundTx, cl::PartialTxInputWitness)>,
     pub zone_in: cl::PartialTxInputWitness,
     pub zone_out: cl::PartialTxOutputWitness,
     /// While the absence of birth constraints does not guarantee uniqueness of a note that can be used as

goas/atomic_asset_transfer/risc0_proofs/zone_state/src/main.rs

@@ -1,5 +1,5 @@
 use cl::{
-    note::NoteWitness, nullifier::NullifierNonce, output::OutputWitness,
+    note::NoteWitness, output::OutputWitness,
     PtxRoot,
 };
 
@@ -39,7 +39,7 @@ fn validate_zone_transition(
     );
 
     // the nonce is correctly evolved
-    assert_eq!(in_note.input.evolved_nonce(), out_note.output.nonce);
+    assert_eq!(in_note.input.evolved_nonce(b"STATE_NONCE"), out_note.output.nonce);
 
     // funds are still under control of the zone
     let expected_note_witness = NoteWitness::new(
@@ -52,7 +52,7 @@ fn validate_zone_transition(
         out_funds.output,
         OutputWitness::public(
             expected_note_witness,
-            NullifierNonce::from_bytes(out_state.nonce)
+            in_note.input.evolved_nonce(b"FUND_NONCE")
         )
     );
     // funds belong to the same partial tx
@@ -78,12 +78,18 @@ fn main() {
 
     let in_state_cm = state.commit();
 
-    for BoundTx { tx, bind } in inputs {
+    for (signed_bound_tx, ptx_input_witness) in inputs {
-        assert_eq!(bind.input_root(), input_root);
+        // verify the signature
-        state = state.apply(tx)
+        let bound_tx = signed_bound_tx.verify_and_unwrap();
+
+        // ensure the note this tx is bound to is present in the ptx
+        assert_eq!(bound_tx.bind, ptx_input_witness.input.note_commitment());
+        assert_eq!(ptx_input_witness.input_root(), input_root);
+
+        // apply the ptx
+        state = state.apply(bound_tx.tx)
     }
 
-    let state = state.evolve_nonce();
     validate_zone_transition(zone_in, zone_out, funds_out, in_state_cm, state);
 
     env::commit(&pub_inputs);

goas/cl/cl/src/input.rs

@@ -52,21 +52,25 @@ impl InputWitness {
         }
     }
 
-    pub fn evolved_nonce(&self) -> NullifierNonce {
+    pub fn evolved_nonce(&self, domain: &[u8]) -> NullifierNonce {
-        self.nonce.evolve(&self.nf_sk)
+        self.nonce.evolve(domain, &self.nf_sk, &self.note)
     }
 
-    pub fn evolve_output(&self, balance_blinding: BalanceWitness) -> crate::OutputWitness {
+    pub fn evolve_output(
+        &self,
+        domain: &[u8],
+        balance_blinding: BalanceWitness,
+    ) -> crate::OutputWitness {
         crate::OutputWitness {
             note: self.note,
             balance_blinding,
             nf_pk: self.nf_sk.commit(),
-            nonce: self.evolved_nonce(),
+            nonce: self.evolved_nonce(domain),
         }
     }
 
     pub fn nullifier(&self) -> Nullifier {
-        Nullifier::new(self.nf_sk, self.nonce)
+        Nullifier::new(self.nf_sk, self.note_commitment())
     }
 
     pub fn commit(&self) -> Input {

goas/cl/cl/src/note.rs

@@ -23,7 +23,7 @@ pub fn unit_point(unit: &str) -> Unit {
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
-pub struct NoteCommitment([u8; 32]);
+pub struct NoteCommitment(pub [u8; 32]);
 
 impl NoteCommitment {
     pub fn as_bytes(&self) -> &[u8; 32] {
@@ -31,8 +31,6 @@ impl NoteCommitment {
     }
 }
 
-// TODO: Rename Note to NoteWitness and NoteCommitment to Note
-
 #[derive(Debug, PartialEq, Eq, Clone, Copy, Serialize, Deserialize)]
 pub struct NoteWitness {
     pub value: u64,

goas/cl/cl/src/nullifier.rs

@@ -9,6 +9,8 @@ use rand_core::RngCore;
 use serde::{Deserialize, Serialize};
 use sha2::{Digest, Sha256};
 
+use crate::{NoteCommitment, NoteWitness};
+
 // TODO: create a nullifier witness and use it throughout.
 // struct NullifierWitness {
 //     nf_sk: NullifierSecret,
@@ -90,11 +92,12 @@ impl NullifierNonce {
         Self(bytes)
     }
 
-    pub fn evolve(&self, nf_sk: &NullifierSecret) -> Self {
+    pub fn evolve(&self, domain: &[u8], nf_sk: &NullifierSecret, note: &NoteWitness) -> Self {
         let mut hasher = Sha256::new();
         hasher.update(b"NOMOS_COIN_EVOLVE");
-        hasher.update(&self.0);
+        hasher.update(domain);
         hasher.update(nf_sk.0);
+        hasher.update(note.commit(nf_sk.commit(), *self).0);
 
         let nonce_bytes: [u8; 32] = hasher.finalize().into();
         Self(nonce_bytes)
@@ -102,11 +105,11 @@ impl NullifierNonce {
 }
 
 impl Nullifier {
-    pub fn new(sk: NullifierSecret, nonce: NullifierNonce) -> Self {
+    pub fn new(sk: NullifierSecret, note_cm: NoteCommitment) -> Self {
         let mut hasher = Sha256::new();
         hasher.update(b"NOMOS_CL_NULLIFIER");
         hasher.update(sk.0);
-        hasher.update(nonce.0);
+        hasher.update(note_cm.0);
 
         let nf_bytes: [u8; 32] = hasher.finalize().into();
         Self(nf_bytes)
@@ -119,6 +122,8 @@ impl Nullifier {
 
 #[cfg(test)]
 mod test {
+    use crate::{note::unit_point, NoteWitness};
+
     use super::*;
 
     #[ignore = "nullifier test vectors not stable yet"]
@@ -142,10 +147,31 @@ mod test {
     fn test_nullifier_same_sk_different_nonce() {
         let mut rng = rand::thread_rng();
         let sk = NullifierSecret::random(&mut rng);
+        let note = NoteWitness::basic(1, unit_point("NMO"));
+
         let nonce_1 = NullifierNonce::random(&mut rng);
         let nonce_2 = NullifierNonce::random(&mut rng);
-        let nf_1 = Nullifier::new(sk, nonce_1);
+        let note_cm_1 = note.commit(sk.commit(), nonce_1);
-        let nf_2 = Nullifier::new(sk, nonce_2);
+        let note_cm_2 = note.commit(sk.commit(), nonce_2);
+
+        let nf_1 = Nullifier::new(sk, note_cm_1);
+        let nf_2 = Nullifier::new(sk, note_cm_2);
+
+        assert_ne!(nf_1, nf_2);
+    }
+
+    #[test]
+    fn test_same_sk_same_nonce_different_note() {
+        let mut rng = rand::thread_rng();
+        let sk = NullifierSecret::random(&mut rng);
+        let note_1 = NoteWitness::basic(1, unit_point("NMO"));
+        let note_2 = NoteWitness::basic(1, unit_point("ETH"));
+        let nonce = NullifierNonce::random(&mut rng);
+        let note_cm_1 = note_1.commit(sk.commit(), nonce);
+        let note_cm_2 = note_2.commit(sk.commit(), nonce);
+
+        let nf_1 = Nullifier::new(sk, note_cm_1);
+        let nf_2 = Nullifier::new(sk, note_cm_2);
 
         assert_ne!(nf_1, nf_2);
     }

goas/cl/ledger/src/input.rs

@@ -127,7 +127,7 @@ mod test {
                 input: cl::Input {
                     nullifier: cl::Nullifier::new(
                         cl::NullifierSecret::random(&mut rng),
-                        cl::NullifierNonce::random(&mut rng),
+                        input.note_commitment(),
                     ),
                     ..expected_public_inputs.input
                 },