diff --git a/hash/risc0/bench/methods/guest/src/bin/blake2b.rs b/hash/risc0/bench/methods/guest/src/bin/blake2b.rs
index 4d6c3e5..87ce9a6 100644
--- a/hash/risc0/bench/methods/guest/src/bin/blake2b.rs
+++ b/hash/risc0/bench/methods/guest/src/bin/blake2b.rs
@@ -2,12 +2,15 @@
 
 use risc0_zkvm::{guest::env, sha::Digest};
 use risc0_zkp::core::hash::blake2b::{Blake2b, Blake2bCpuImpl};
+use std::io::Read;
 
 risc0_zkvm::guest::entry!(main);
 
 pub fn main() {
 
-    let data: Vec<u8> = env::read();
+    let mut data = Vec::<u8>::new();
+    env::stdin().read_to_end(&mut data).unwrap();
+
     let hash = Blake2bCpuImpl::blake2b(&data);
     let digest: Digest = hash.into();
     env::commit(&digest)
diff --git a/hash/risc0/bench/methods/guest/src/bin/blake3.rs b/hash/risc0/bench/methods/guest/src/bin/blake3.rs
index fc78b7a..ce639a6 100644
--- a/hash/risc0/bench/methods/guest/src/bin/blake3.rs
+++ b/hash/risc0/bench/methods/guest/src/bin/blake3.rs
@@ -2,12 +2,15 @@
 
 use risc0_zkvm::{guest::env, sha::Digest};
 use blake3::hash;
+use std::io::Read;
 
 risc0_zkvm::guest::entry!(main);
 
 pub fn main() {
 
-    let data: Vec<u8> = env::read();
+    let mut data = Vec::<u8>::new();
+    env::stdin().read_to_end(&mut data).unwrap();
+
     let result = hash(&data);
     let digest = Digest::try_from(*result.as_bytes()).unwrap();
     env::commit(&digest)
diff --git a/hash/risc0/bench/methods/guest/src/bin/keccak.rs b/hash/risc0/bench/methods/guest/src/bin/keccak.rs
index c28e7e0..dcd4b7d 100644
--- a/hash/risc0/bench/methods/guest/src/bin/keccak.rs
+++ b/hash/risc0/bench/methods/guest/src/bin/keccak.rs
@@ -2,12 +2,15 @@
 
 use risc0_zkvm::{guest::env, sha::Digest};
 use sha3::{Digest as _, Keccak256};
+use std::io::Read;
 
 risc0_zkvm::guest::entry!(main);
 
 pub fn main() {
 
-    let data: Vec<u8> = env::read();
+    let mut data = Vec::<u8>::new();
+    env::stdin().read_to_end(&mut data).unwrap();
+
     let hash: [u8;32] = Keccak256::digest(data).into();
     let digest  = Digest::try_from(hash).unwrap();
     env::commit(&digest)
diff --git a/hash/risc0/bench/methods/guest/src/bin/sha256.rs b/hash/risc0/bench/methods/guest/src/bin/sha256.rs
index 185a9d7..f6b1b74 100644
--- a/hash/risc0/bench/methods/guest/src/bin/sha256.rs
+++ b/hash/risc0/bench/methods/guest/src/bin/sha256.rs
@@ -1,13 +1,17 @@
 #![no_main]
 
+use std::io::Read;
 use risc0_zkvm::{guest::env, sha, sha::Sha256};
 risc0_zkvm::guest::entry!(main);
 use risc0_zkvm::guest::env::cycle_count;
 
 pub fn main() {
-
-    let data: Vec<u8> = env::read();
+    let start = cycle_count();
+    let mut data = Vec::<u8>::new();
+    env::stdin().read_to_end(&mut data).unwrap();
+    let end = cycle_count();
     let hash = sha::Impl::hash_bytes(&data);
+    eprintln!("total cycle count for input: {:?}",end - start);
     eprintln!("total cycle count for hashing: {:?}",cycle_count());
     env::commit(&hash)
 }
diff --git a/hash/risc0/bench/methods/guest/src/bin/sha256_accelerated.rs b/hash/risc0/bench/methods/guest/src/bin/sha256_accelerated.rs
index 2162da4..2aecc65 100644
--- a/hash/risc0/bench/methods/guest/src/bin/sha256_accelerated.rs
+++ b/hash/risc0/bench/methods/guest/src/bin/sha256_accelerated.rs
@@ -1,7 +1,7 @@
 
 // accelerated sha2 crate
 #![no_main]
-
+use std::io::Read;
 use risc0_zkvm::guest::env;
 use sha2::{Sha256, Digest};
 use risc0_zkvm::guest::env::cycle_count;
@@ -10,7 +10,9 @@ risc0_zkvm::guest::entry!(main);
 
 pub fn main() {
 
-    let data: Vec<u8> = env::read();
+    let mut data = Vec::<u8>::new();
+    env::stdin().read_to_end(&mut data).unwrap();
+
     let result = Sha256::digest(data);
     let c1 = cycle_count();
     eprintln!("total cycle count for hashing: {:?}",c1);
diff --git a/hash/risc0/bench/src/benches/blake2b.rs b/hash/risc0/bench/src/benches/blake2b.rs
index 75bbf05..1d928fc 100644
--- a/hash/risc0/bench/src/benches/blake2b.rs
+++ b/hash/risc0/bench/src/benches/blake2b.rs
@@ -8,7 +8,10 @@ use std::time::Instant;
 
 pub fn blake2b_bench(input: Vec<u8>) {
    
-    let env = ExecutorEnv::builder().write(&input).unwrap().build().unwrap();
+    let env = ExecutorEnv::builder()
+      .write_slice(&input)
+      .build()
+      .unwrap();
 
     // Obtain the default prover.
     let prover = default_prover();
diff --git a/hash/risc0/bench/src/benches/blake3.rs b/hash/risc0/bench/src/benches/blake3.rs
index 2f12a7f..38e85cc 100644
--- a/hash/risc0/bench/src/benches/blake3.rs
+++ b/hash/risc0/bench/src/benches/blake3.rs
@@ -7,10 +7,11 @@ use risc0_zkvm::{ sha};
 use std::time::Instant;
 
 pub fn blake3_bench(input: Vec<u8>) {
-   
-    
 
-    let env = ExecutorEnv::builder().write(&input).unwrap().build().unwrap();
+    let env = ExecutorEnv::builder()
+      .write_slice(&input)
+      .build()
+      .unwrap();
 
     // Obtain the default prover.
     let prover = default_prover();
diff --git a/hash/risc0/bench/src/benches/keccak.rs b/hash/risc0/bench/src/benches/keccak.rs
index 73c8506..6369492 100644
--- a/hash/risc0/bench/src/benches/keccak.rs
+++ b/hash/risc0/bench/src/benches/keccak.rs
@@ -7,14 +7,17 @@ use risc0_zkvm::{ sha};
 use std::time::Instant;
 
 pub fn keccak_bench(input: Vec<u8>) {
-   
-    let start_time = Instant::now();
-
-    let env = ExecutorEnv::builder().write(&input).unwrap().build().unwrap();
 
+    let env = ExecutorEnv::builder()
+      .write_slice(&input)
+      .build()
+      .unwrap();
+    
     // Obtain the default prover.
     let prover = default_prover();
 
+    let start_time = Instant::now();
+    
     // Produce a receipt by proving the specified ELF binary.
     let receipt = prover.prove(env, KECCAK_ELF).unwrap();
 
diff --git a/hash/risc0/bench/src/benches/sha256.rs b/hash/risc0/bench/src/benches/sha256.rs
index 1777f56..df6113b 100644
--- a/hash/risc0/bench/src/benches/sha256.rs
+++ b/hash/risc0/bench/src/benches/sha256.rs
@@ -4,10 +4,14 @@ use benchmark_methods::{
 use risc0_zkvm::{default_prover, ExecutorEnv};
 use risc0_zkvm::{ sha};
 use std::time::Instant;
+
 pub fn sha_bench(input: Vec<u8>) {
    
-    let env = ExecutorEnv::builder().write(&input).unwrap().build().unwrap();
-
+    let env = ExecutorEnv::builder()
+      .write_slice(&input)
+      .build()
+      .unwrap();
+    
     // Obtain the default prover.
     let prover = default_prover();
     eprintln!("\n------risc0_zkvm sha hashing------\n");
diff --git a/hash/risc0/bench/src/benches/sha256_accelerated.rs b/hash/risc0/bench/src/benches/sha256_accelerated.rs
index 6233cae..a979f0b 100644
--- a/hash/risc0/bench/src/benches/sha256_accelerated.rs
+++ b/hash/risc0/bench/src/benches/sha256_accelerated.rs
@@ -6,7 +6,11 @@ use std::time::Instant;
 use hex::encode;
 pub fn sha_accelerated_bench(input: Vec<u8>) {
    
-    let env = ExecutorEnv::builder().write(&input).unwrap().build().unwrap();
+    let env = ExecutorEnv::builder()
+      .write_slice(&input)
+      .build()
+      .unwrap();
+    
     eprintln!("\n------RustCrypto sha hashing(accelerated)------\n");
     // Obtain the default prover.
     let prover = default_prover();
diff --git a/hash/risc0/external/risc0 b/hash/risc0/external/risc0
index 1742ef8..02fad7a 160000
--- a/hash/risc0/external/risc0
+++ b/hash/risc0/external/risc0
@@ -1 +1 @@
-Subproject commit 1742ef8098d246871055501a0559811c9a8fece4
+Subproject commit 02fad7a498764d5c6cc851f246813b73b41c30b8