diff --git a/hash/jolt/bench/guest/src/lib.rs b/hash/jolt/bench/guest/src/lib.rs
index 3398b90..f3f979a 100644
--- a/hash/jolt/bench/guest/src/lib.rs
+++ b/hash/jolt/bench/guest/src/lib.rs
@@ -4,7 +4,7 @@
 use sha2::{Sha256, Digest};
 use sha3::Keccak256;
 use blake3::hash;
-use blake2::Blake2s256;
+use blake2::Blake2b512;
 
 use risc0_zkp::core::hash::poseidon2::Poseidon2HashSuite;
 use risc0_zkp::field::baby_bear::BabyBearElem;
@@ -39,25 +39,27 @@ fn blake3(input: &[u8]) -> [u8; 32] {
 
 // blake2
 #[jolt::provable]
-fn blake2(input: &[u8]) -> [u8; 32] {
-    let mut hasher = Blake2s256::new();
+fn blake2(input: &[u8]) -> Vec<u8> {
+    let mut hasher = Blake2b512::new();
     hasher.update(input);
     let result = hasher.finalize();
-    Into::<[u8; 32]>::into(result)
+    
+    result.to_vec()
 }
 
 // poseidon2 over babybear
 #[jolt::provable(stack_size = 10000, memory_size = 100000000)]
-//TODO: input should be made u32
-fn poseidon2_babybear(input: &[u8]) -> String {
+fn poseidon2_babybear(input: Vec<u32>) -> Vec<u32> {
     let mut hash_data: Vec<BabyBearElem> = Vec::new();
 
     for i in 0..input.len() {
         let a_uncompressed = BabyBearElem::from(input[i] as u32);
         hash_data.push(a_uncompressed);
     }
-    let result = Poseidon2HashSuite::new_suite().hashfn.hash_elem_slice(hash_data.as_slice());
 
-    result.to_string()
+    let mut binding = Poseidon2HashSuite::new_suite().hashfn.hash_elem_slice(hash_data.as_slice());
+    let result = binding.as_mut_words().to_vec();
+
+    result
     
 }
\ No newline at end of file
diff --git a/hash/jolt/bench/src/benches/poseidon2_babybear.rs b/hash/jolt/bench/src/benches/poseidon2_babybear.rs
index bc5ece9..29eb992 100644
--- a/hash/jolt/bench/src/benches/poseidon2_babybear.rs
+++ b/hash/jolt/bench/src/benches/poseidon2_babybear.rs
@@ -8,12 +8,12 @@ use alloc::vec::Vec;
 pub fn poseidon2_babybear_bench(mt_depth: usize) {
 
     let t = (1 << mt_depth) * 8;
-    let mut input: Vec<u8> = Vec::new();
+    let mut input: Vec<u32> = Vec::new();
 
     for _ in 0..t {
         
         let mut rng = rand::thread_rng();
-        let random_u32: u8 = rng.gen();
+        let random_u32: u32 = rng.gen();
         input.push(random_u32);
     }
 
@@ -29,7 +29,7 @@ pub fn poseidon2_babybear_bench(mt_depth: usize) {
     let (output, proof, proving_time) = {
 
         let start = Instant::now();
-        let (output, proof) = prove_poseidon2_babybear(input.as_slice());
+        let (output, proof) = prove_poseidon2_babybear(input);
         let elapsed = start.elapsed();
 
         (output, proof, elapsed)
@@ -47,8 +47,13 @@ pub fn poseidon2_babybear_bench(mt_depth: usize) {
         (is_valid, elapsed)
     };
 
+    let mut output_bytes: Vec<u8> = Vec::new();
+    for i in 0..8 {
+        output_bytes.extend_from_slice(output[i].to_be_bytes().as_slice());
+    }
+    
     assert!(is_valid);
-    println!("output: {:?}", hex::encode(output));
+    println!("output: {:?}", hex::encode(&output_bytes));
     println!("guest build time: {:?}", guest_build_time);
     println!("proving time: {:?}", proving_time);
     println!("verification time: {:?}", verification_time);