diff --git a/Cargo.lock b/Cargo.lock
index 1eb4b4f5c1..4d8fdbe5dc 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1338,6 +1338,15 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "keccak"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ecc2af9a1119c51f12a14607e783cb977bde58bc069ff0c3da1095e635d70654"
+dependencies = [
+ "cpufeatures",
+]
+
 [[package]]
 name = "kernel32-sys"
 version = "0.2.2"
@@ -1467,6 +1476,7 @@ dependencies = [
  "serde",
  "serde_json",
  "serde_with 3.6.0",
+ "sha3",
  "strum",
  "strum_macros",
 ]
@@ -2557,6 +2567,16 @@ dependencies = [
  "digest 0.10.7",
 ]
 
+[[package]]
+name = "sha3"
+version = "0.10.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "75872d278a8f37ef87fa0ddbda7802605cb18344497949862c0d4dcb291eba60"
+dependencies = [
+ "digest 0.10.7",
+ "keccak",
+]
+
 [[package]]
 name = "shell-words"
 version = "1.1.0"
diff --git a/Cargo.toml b/Cargo.toml
index 29a04df896..b4ae4197a4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -68,6 +68,7 @@ serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0.79"
 serde_with = "3.6.0"
 sha2 = "0.10.0"
+sha3 = "0.10.8"
 strum = "0.26.1"
 strum_macros = "0.26.1"
 syn = { version = "1.0.109", features = ["full"] }
diff --git a/optimism/Cargo.toml b/optimism/Cargo.toml
index c163729985..b57d3186f0 100644
--- a/optimism/Cargo.toml
+++ b/optimism/Cargo.toml
@@ -46,3 +46,4 @@ os_pipe.workspace = true
 rand.workspace = true
 libc.workspace = true
 rayon.workspace = true
+sha3.workspace = true
\ No newline at end of file
diff --git a/optimism/src/keccak/mod.rs b/optimism/src/keccak/mod.rs
index 041067d44c..cc950356e0 100644
--- a/optimism/src/keccak/mod.rs
+++ b/optimism/src/keccak/mod.rs
@@ -10,6 +10,8 @@ pub mod column;
 pub mod constraints;
 pub mod environment;
 pub mod interpreter;
+#[cfg(test)]
+pub mod tests;
 pub mod witness;
 
 /// Desired output length of the hash in bits
diff --git a/optimism/src/keccak/tests.rs b/optimism/src/keccak/tests.rs
new file mode 100644
index 0000000000..d771ea2fd8
--- /dev/null
+++ b/optimism/src/keccak/tests.rs
@@ -0,0 +1,53 @@
+use crate::keccak::{environment::KeccakEnv, interpreter::KeccakInterpreter};
+use kimchi::o1_utils::{self, FieldHelpers};
+use mina_curves::pasta::Fp;
+use rand::Rng;
+use sha3::{Digest, Keccak256};
+
+#[test]
+fn test_pad_blocks() {
+    let blocks_1 = crate::keccak::pad_blocks::<Fp>(1);
+    assert_eq!(blocks_1[0], Fp::from(0x00));
+    assert_eq!(blocks_1[1], Fp::from(0x00));
+    assert_eq!(blocks_1[2], Fp::from(0x00));
+    assert_eq!(blocks_1[3], Fp::from(0x00));
+    assert_eq!(blocks_1[4], Fp::from(0x81));
+
+    let blocks_136 = crate::keccak::pad_blocks::<Fp>(136);
+    assert_eq!(blocks_136[0], Fp::from(0x010000000000000000000000u128));
+    assert_eq!(blocks_136[1], Fp::from(0x00));
+    assert_eq!(blocks_136[2], Fp::from(0x00));
+    assert_eq!(blocks_136[3], Fp::from(0x00));
+    assert_eq!(blocks_136[4], Fp::from(0x80));
+}
+
+#[test]
+fn test_keccak_witness_satisfies_constraints() {
+    let mut rng = o1_utils::tests::make_test_rng();
+
+    // Generate random bytelength and preimage for Keccak
+    let bytelength = rng.gen_range(1..1000);
+    let preimage: Vec<u8> = (0..bytelength).map(|_| rng.gen()).collect();
+    // Use an external library to compute the hash
+    let mut hasher = Keccak256::new();
+    hasher.update(&preimage);
+    let hash = hasher.finalize();
+
+    // Initialize the environment and run the interpreter
+    let mut keccak_env = KeccakEnv::<Fp>::new(0, &preimage);
+    while keccak_env.keccak_step.is_some() {
+        keccak_env.step();
+        // Simulate the constraints for each row (still checks nothing about lookups)
+        keccak_env.witness_env.constraints();
+    }
+    // Extract the hash from the witness
+    let output = keccak_env.witness_env.sponge_bytes()[0..32]
+        .iter()
+        .map(|byte| byte.to_bytes()[0])
+        .collect::<Vec<_>>();
+
+    // Check that the hash matches
+    for (i, byte) in output.iter().enumerate() {
+        assert_eq!(*byte, hash[i]);
+    }
+}