diff --git a/core/src/crypto/hash.rs b/core/src/crypto/hash.rs
index d907a648..7ff9e460 100644
--- a/core/src/crypto/hash.rs
+++ b/core/src/crypto/hash.rs
@@ -4,7 +4,7 @@ use plonky2::field::goldilocks_field::GoldilocksField;
 
 pub trait Hasher<Hash> {
     /// Gets the hash of the byte sequence.
-    fn hash_bytes<I: IntoIterator<Item = GoldilocksField>>(&self, value: I) -> Hash;
+    fn hash_bytes(&self, value: &Vec<GoldilocksField>) -> Hash;
     /// Get the hash of the hashes sequence.
     fn hash_elements<I: IntoIterator<Item = Hash>>(&self, elements: I) -> Hash;
     /// Merges two hashes into one.
diff --git a/core/src/crypto/poseidon.rs b/core/src/crypto/poseidon.rs
index fe6a29ab..178ffa9f 100644
--- a/core/src/crypto/poseidon.rs
+++ b/core/src/crypto/poseidon.rs
@@ -15,9 +15,8 @@ use plonky2::hash::poseidon::PoseidonPermutation;
 pub struct PoseidonHasher;
 
 impl Hasher<TreeValue> for PoseidonHasher {
-    fn hash_bytes<I: IntoIterator<Item = GoldilocksField>>(&self, value: I) -> TreeValue {
-        let value_iter: Vec<_> = value.into_iter().collect();
-        hash_n_to_hash_no_pad::<GoldilocksField, PoseidonPermutation>(&value_iter).elements
+    fn hash_bytes(&self, value: &Vec<GoldilocksField>) -> TreeValue {
+        hash_n_to_hash_no_pad::<GoldilocksField, PoseidonPermutation>(&value).elements
     }
 
     /// Get the hash of the hashes sequence.
diff --git a/core/src/state/mod.rs b/core/src/state/mod.rs
index 325fd86c..e423be56 100644
--- a/core/src/state/mod.rs
+++ b/core/src/state/mod.rs
@@ -40,7 +40,7 @@ where
     ) -> Result<Vec<TreeValue>, StateError> {
         let mut code_hashes = Vec::new();
         for code in contracts {
-            code_hashes.push(self.hasher.hash_bytes(code.clone()));
+            code_hashes.push(self.hasher.hash_bytes(&code));
         }
         self.state_storage
             .save_contracts(&code_hashes, &contracts)?;
@@ -51,7 +51,7 @@ where
         &mut self,
         contract: &Vec<GoldilocksField>,
     ) -> Result<TreeValue, StateError> {
-        let code_hash = self.hasher.hash_bytes(contract.clone());
+        let code_hash = self.hasher.hash_bytes(&contract);
         self.state_storage.save_contract(&code_hash, &contract)?;
         return Ok(code_hash);
     }
diff --git a/core/src/trace/trace.rs b/core/src/trace/trace.rs
index 9e635de0..a04aa701 100644
--- a/core/src/trace/trace.rs
+++ b/core/src/trace/trace.rs
@@ -320,7 +320,7 @@ pub struct Trace {
     // pub raw_instructions: HashMap<u64, Instruction>,
     pub raw_instructions: HashMap<u64, String>,
     pub raw_binary_instructions: Vec<String>,
-    pub addr_program_hash: HashMap<String, TreeValue>,
+    pub addr_program_hash: HashMap<String, Vec<GoldilocksField>>,
     pub start_end_roots: (TreeValue, TreeValue),
     // todo need limit the trace size
     pub exec: Vec<Step>,
diff --git a/executor/src/tests.rs b/executor/src/tests.rs
index b0b27d27..90b3577e 100644
--- a/executor/src/tests.rs
+++ b/executor/src/tests.rs
@@ -43,7 +43,7 @@ fn executor_run_test_program(
         .clone()
         .map(|e| GoldilocksField::from_canonical_u64(u64::from_str_radix(&e[2..], 16).unwrap()))
         .collect();
-    let code_hash = hash.hash_bytes(code);
+    let code_hash = hash.hash_bytes(&code);
     let mut prophets = HashMap::new();
     for item in program.prophets {
         prophets.insert(item.host as u64, item);
@@ -99,7 +99,7 @@ fn executor_run_test_program(
     program
         .trace
         .addr_program_hash
-        .insert(encode_addr(&callee_exe_addr), code_hash);
+        .insert(encode_addr(&callee_exe_addr), code);
     let mut account_tree = AccountTree::new_test();
     //let mut account_tree =AccountTree::new_db_test("./".to_string()),
 
diff --git a/zk-vm/src/lib.rs b/zk-vm/src/lib.rs
index 7714ac53..968899ef 100644
--- a/zk-vm/src/lib.rs
+++ b/zk-vm/src/lib.rs
@@ -144,7 +144,7 @@ impl OlaVM {
 
         if get_code {
             let contract = self.get_contract(&code_hash)?;
-            for inst in contract {
+            for inst in &contract {
                 program
                     .instructions
                     .push(format!("0x{:x}", inst.to_canonical_u64()));
@@ -162,7 +162,7 @@ impl OlaVM {
             program
                 .trace
                 .addr_program_hash
-                .insert(encode_addr(&exe_code_addr), code_hash);
+                .insert(encode_addr(&exe_code_addr),  contract);
         }
 
         let prophet = self.get_prophet(&code_hash).unwrap();