diff --git a/README.md b/README.md
index a152c94..9b1efd6 100644
--- a/README.md
+++ b/README.md
@@ -27,8 +27,10 @@ Single core, unoptimized, MacBook Pro M2.
 
 - 1000 Poseidon2 permutations: 5.24 msec (approx 12MB/sec linear hashing)
 - 1000 Griffin permutations: 76.8 msec  (appox 800k/sec linear hashing)
+- 1000 Skyscraper permutations: 207.45 µs (width=2)
 
 10000 permutations:
 
 - 10000 Poseidon2 permutations: 53 msec
-- 10000 Griffin permutations: 762 sec
+- 10000 Griffin permutations: 762 msec
+- 10000 Skyscraper permutations: 2.2 msec (width=2)
diff --git a/benches/iterated_perm.rs b/benches/iterated_perm.rs
index 9da216f..210dd69 100644
--- a/benches/iterated_perm.rs
+++ b/benches/iterated_perm.rs
@@ -22,8 +22,9 @@ fn bench_iterated_perm(c: &mut Criterion , h: Hash, n: usize) {
 //------------------------------------------------------------------------------
 
 fn bench_permutations(c: &mut Criterion) {
-  bench_iterated_perm(c, Hash::Poseidon2, 1000);
-  bench_iterated_perm(c, Hash::Griffin  , 1000);
+  bench_iterated_perm(c, Hash::Poseidon2, 10000);
+  bench_iterated_perm(c, Hash::Griffin  , 10000);
+  bench_iterated_perm(c, Hash::Skyscraper  , 10000);
 }
 
 //------------------------------------------------------------------------------
diff --git a/src/hash.rs b/src/hash.rs
index 80911a3..de72bb0 100644
--- a/src/hash.rs
+++ b/src/hash.rs
@@ -12,6 +12,7 @@ use crate::griffin;
 pub enum Hash {
   Poseidon2,
   Griffin,
+  Skyscraper
 }
 
 //------------------------------------------------------------------------------
@@ -20,6 +21,7 @@ pub fn permute(h: Hash, s: State) -> State {
   match h {
     Hash::Poseidon2 => poseidon2::permutation::permute(s),
     Hash::Griffin   =>   griffin::permutation::permute(s),
+    Hash::Skyscraper   =>   skyscraper::permutation::permute_state(s),
   }
 }
 
@@ -27,6 +29,7 @@ pub fn permute_inplace(h: Hash, s: &mut State){
   match h {
     Hash::Poseidon2 => poseidon2::permutation::permute_inplace(s),
     Hash::Griffin   =>   griffin::permutation::permute_inplace(s),
+    Hash::Skyscraper   =>   skyscraper::permutation::permute_state_inplace(s),
   };
 }
 
diff --git a/src/skyscraper/permutation.rs b/src/skyscraper/permutation.rs
index 30cb9dd..a7dd194 100644
--- a/src/skyscraper/permutation.rs
+++ b/src/skyscraper/permutation.rs
@@ -1,7 +1,9 @@
 use ark_bn254::{Fr as F};
 use ark_ff::{BigInteger256, Field, One, PrimeField};
 use core::str::FromStr;
+use std::os::macos::raw::stat;
 use crate::skyscraper::constants::{FunctionBlock, RF1, RC, RC_RAW};
+use crate::state::State;
 
 pub fn bars_inplace_mont(x: &mut F) {
     // x → two 128‐bit chunks.
@@ -118,6 +120,21 @@ pub fn permute(input: [F; 2]) -> [F; 2] {
     current_state
 }
 
+/// WARNING: this ignores the z element of the state
+/// TODO: extension field
+pub fn permute_state_inplace(u: &mut State) {
+    let ns = permute([u.x,u.y]);
+    u.x = ns[0];
+    u.y = ns[1];
+}
+
+/// WARNING: this ignores the z element of the state
+/// TODO: extension field
+pub fn permute_state(mut u: State) -> State{
+    permute_state_inplace(&mut u);
+    u
+}
+
 pub fn compress(x: F, y: F) -> F {
     let p_out = permute([x, y]);
     let out = x + p_out[0];
@@ -129,7 +146,7 @@ mod tests {
     use super::*;
 
     #[test]
-    fn test_k_permutation() {
+    fn test_permutation() {
         let init = [F::from(1234u64), F::from(5678u64)];
         let init_mont = [F::new_unchecked(init[0].into_bigint()), F::new_unchecked(init[1].into_bigint())];
         let out = permute(init_mont);