diff --git a/crates/zkvm-interface/platform/Cargo.toml b/crates/zkvm-interface/platform/Cargo.toml
index 9945640..63d7fc7 100644
--- a/crates/zkvm-interface/platform/Cargo.toml
+++ b/crates/zkvm-interface/platform/Cargo.toml
@@ -6,11 +6,10 @@ rust-version.workspace = true
 license.workspace = true
 
 [dependencies]
-digest = { workspace = true, optional = true }
+digest.workspace = true
 
 [features]
 default = []
-output-hasher = ["dep:digest"]
 
 [lints]
 workspace = true
diff --git a/crates/zkvm-interface/platform/src/lib.rs b/crates/zkvm-interface/platform/src/lib.rs
index 5aa537d..1a0da81 100644
--- a/crates/zkvm-interface/platform/src/lib.rs
+++ b/crates/zkvm-interface/platform/src/lib.rs
@@ -4,7 +4,6 @@ extern crate alloc;
 
 use alloc::vec::Vec;
 
-#[cfg(feature = "output-hasher")]
 pub mod output_hasher;
 
 /// Platform dependent methods.
diff --git a/crates/zkvm-interface/platform/src/output_hasher.rs b/crates/zkvm-interface/platform/src/output_hasher.rs
index c252196..58c4b7b 100644
--- a/crates/zkvm-interface/platform/src/output_hasher.rs
+++ b/crates/zkvm-interface/platform/src/output_hasher.rs
@@ -1,23 +1,50 @@
-use core::marker::PhantomData;
-use digest::{Digest, Output, OutputSizeUser, generic_array::ArrayLength};
+use core::{marker::PhantomData, ops::Deref};
+use digest::{
+    Digest, Output, OutputSizeUser,
+    generic_array::{ArrayLength, GenericArray},
+};
 
 pub use digest;
 
-/// A hasher that given the output, returns a fixed size hash of it.
-pub trait OutputHasher: OutputSizeUser {
-    fn output_hash(output: &[u8]) -> Output<Self>;
+/// A hasher that given the output, returns a hash of it.
+pub trait OutputHasher {
+    type Hash<'a>: Deref<Target = [u8]>;
+
+    fn output_hash(output: &[u8]) -> Self::Hash<'_>;
 }
 
-/// [`OutputHasher`] implementation that expects the output size to be equal to
-/// the fixed size, and returns it as is.
-pub struct IdentityOutput<S>(PhantomData<S>);
+/// A hasher that given the output, returns a fixed-size hash of it.
+pub trait FixedOutputHasher: OutputHasher + OutputSizeUser {}
 
-impl<S: ArrayLength<u8> + 'static> OutputSizeUser for IdentityOutput<S> {
-    type OutputSize = S;
+impl<T: OutputHasher + OutputSizeUser> FixedOutputHasher for T {}
+
+/// A marker used to mark [`IdentityOutput`] to accept unsized output.
+pub struct Unsized;
+
+/// [`OutputHasher`] implementation that returns output as is.
+///
+/// By setting generic `U = Unsized` it takes output with any size.
+///
+/// By setting generic `U = typenum::U{SIZE}` it expects the output to match
+/// the `SIZE`.
+pub struct IdentityOutput<U = Unsized>(PhantomData<U>);
+
+impl OutputHasher for IdentityOutput<Unsized> {
+    type Hash<'a> = &'a [u8];
+
+    fn output_hash(output: &[u8]) -> Self::Hash<'_> {
+        output
+    }
 }
 
-impl<S: ArrayLength<u8> + 'static> OutputHasher for IdentityOutput<S> {
-    fn output_hash(output: &[u8]) -> Output<Self> {
+impl<U: ArrayLength<u8> + 'static> OutputSizeUser for IdentityOutput<U> {
+    type OutputSize = U;
+}
+
+impl<U: ArrayLength<u8> + 'static> OutputHasher for IdentityOutput<U> {
+    type Hash<'a> = GenericArray<u8, U>;
+
+    fn output_hash(output: &[u8]) -> Self::Hash<'_> {
         assert!(
             output.len() == Self::output_size(),
             "output length should be equal to {}",
@@ -29,16 +56,20 @@ impl<S: ArrayLength<u8> + 'static> OutputHasher for IdentityOutput<S> {
     }
 }
 
-/// [`OutputHasher`] implementation that expects the output size to be less than
-/// or equal to the fixed size, and returns it with 0s padding.
-pub struct PaddedOutput<S>(PhantomData<S>);
+/// [`OutputHasher`] implementation that returns output with 0s padding.
+///
+/// By setting generic `U = typenum::U{SIZE}` it expects the output to be less
+/// than or equal to the `SIZE`.
+pub struct PaddedOutput<U>(PhantomData<U>);
 
-impl<S: ArrayLength<u8> + 'static> OutputSizeUser for PaddedOutput<S> {
-    type OutputSize = S;
+impl<U: ArrayLength<u8> + 'static> OutputSizeUser for PaddedOutput<U> {
+    type OutputSize = U;
 }
 
-impl<S: ArrayLength<u8> + 'static> OutputHasher for PaddedOutput<S> {
-    fn output_hash(output: &[u8]) -> Output<Self> {
+impl<U: ArrayLength<u8> + 'static> OutputHasher for PaddedOutput<U> {
+    type Hash<'a> = GenericArray<u8, U>;
+
+    fn output_hash(output: &[u8]) -> Self::Hash<'_> {
         assert!(
             output.len() <= Self::output_size(),
             "output length should be less than or equal to {}",
@@ -51,7 +82,9 @@ impl<S: ArrayLength<u8> + 'static> OutputHasher for PaddedOutput<S> {
 }
 
 impl<D: Digest> OutputHasher for D {
-    fn output_hash(output: &[u8]) -> Output<Self> {
+    type Hash<'a> = Output<D>;
+
+    fn output_hash(output: &[u8]) -> Self::Hash<'_> {
         D::digest(output)
     }
 }
diff --git a/crates/zkvm/airbender/platform/Cargo.toml b/crates/zkvm/airbender/platform/Cargo.toml
index 21e98b4..379b0c7 100644
--- a/crates/zkvm/airbender/platform/Cargo.toml
+++ b/crates/zkvm/airbender/platform/Cargo.toml
@@ -10,7 +10,7 @@ license.workspace = true
 airbender_riscv_common.workspace = true
 
 # Local dependencies
-ere-platform-trait = { workspace = true, features = ["output-hasher"] }
+ere-platform-trait.workspace = true
 
 [features]
 default = []
diff --git a/crates/zkvm/airbender/platform/src/lib.rs b/crates/zkvm/airbender/platform/src/lib.rs
index 08d2ebc..2d156b5 100644
--- a/crates/zkvm/airbender/platform/src/lib.rs
+++ b/crates/zkvm/airbender/platform/src/lib.rs
@@ -4,17 +4,17 @@ extern crate alloc;
 
 use alloc::vec::Vec;
 use core::{array, iter::repeat_with, marker::PhantomData};
-use ere_platform_trait::output_hasher::{OutputHasher, digest::typenum::U32};
+use ere_platform_trait::output_hasher::FixedOutputHasher;
 
 pub use airbender_riscv_common as riscv_common;
 pub use ere_platform_trait::{
     Platform,
-    output_hasher::{IdentityOutput, PaddedOutput},
+    output_hasher::{IdentityOutput, PaddedOutput, digest::typenum::U32},
 };
 
-pub struct AirbenderPlatform<D>(PhantomData<D>);
+pub struct AirbenderPlatform<H>(PhantomData<H>);
 
-impl<D: OutputHasher<OutputSize = U32>> Platform for AirbenderPlatform<D> {
+impl<H: FixedOutputHasher<OutputSize = U32>> Platform for AirbenderPlatform<H> {
     fn read_whole_input() -> Vec<u8> {
         let len = riscv_common::csr_read_word() as usize;
         repeat_with(riscv_common::csr_read_word)
@@ -25,7 +25,7 @@ impl<D: OutputHasher<OutputSize = U32>> Platform for AirbenderPlatform<D> {
     }
 
     fn write_whole_output(output: &[u8]) {
-        let hash = D::output_hash(output);
+        let hash = H::output_hash(output);
         let words = array::from_fn(|i| u32::from_le_bytes(array::from_fn(|j| hash[4 * i + j])));
         riscv_common::zksync_os_finish_success(&words);
     }
diff --git a/crates/zkvm/jolt/platform/src/lib.rs b/crates/zkvm/jolt/platform/src/lib.rs
index ed5b7e7..464dd68 100644
--- a/crates/zkvm/jolt/platform/src/lib.rs
+++ b/crates/zkvm/jolt/platform/src/lib.rs
@@ -4,8 +4,12 @@ extern crate alloc;
 
 use alloc::vec::Vec;
 use core::{marker::PhantomData, slice};
+use ere_platform_trait::output_hasher::OutputHasher;
 
-pub use ere_platform_trait::Platform;
+pub use ere_platform_trait::{
+    Platform,
+    output_hasher::{IdentityOutput, PaddedOutput, digest::typenum},
+};
 pub use jolt_sdk as jolt;
 
 // FIXME: Because the crate `jolt-common` is not `no_std` compatible, so we have
@@ -65,9 +69,9 @@ impl JoltMemoryConfig for DefaulJoltMemoryConfig {
     const MEMORY_SIZE: u64 = DEFAULT_MEMORY_SIZE;
 }
 
-pub struct JoltPlatform<C = DefaulJoltMemoryConfig>(PhantomData<C>);
+pub struct JoltPlatform<C = DefaulJoltMemoryConfig, H = IdentityOutput>(PhantomData<(C, H)>);
 
-impl<C: JoltMemoryConfig> Platform for JoltPlatform<C> {
+impl<C: JoltMemoryConfig, H: OutputHasher> Platform for JoltPlatform<C, H> {
     fn read_whole_input() -> Vec<u8> {
         let memory_layout = C::memory_layout();
         let input_ptr = memory_layout.input_start as *const u8;
@@ -78,10 +82,11 @@ impl<C: JoltMemoryConfig> Platform for JoltPlatform<C> {
     }
 
     fn write_whole_output(output: &[u8]) {
+        let hash = H::output_hash(output);
         let memory_layout = C::memory_layout();
         let output_ptr = memory_layout.output_start as *mut u8;
         let max_output_len = memory_layout.max_output_size as usize;
         let output_slice = unsafe { core::slice::from_raw_parts_mut(output_ptr, max_output_len) };
-        jolt::postcard::to_slice(output, output_slice).unwrap();
+        jolt::postcard::to_slice(&*hash, output_slice).unwrap();
     }
 }
diff --git a/crates/zkvm/nexus/platform/src/lib.rs b/crates/zkvm/nexus/platform/src/lib.rs
index 8b4ccb1..8dabcb4 100644
--- a/crates/zkvm/nexus/platform/src/lib.rs
+++ b/crates/zkvm/nexus/platform/src/lib.rs
@@ -3,18 +3,24 @@
 extern crate alloc;
 
 use alloc::vec::Vec;
+use core::marker::PhantomData;
+use ere_platform_trait::output_hasher::OutputHasher;
 
-pub use ere_platform_trait::Platform;
+pub use ere_platform_trait::{
+    Platform,
+    output_hasher::{IdentityOutput, PaddedOutput, digest::typenum},
+};
 pub use nexus_rt;
 
-pub struct NexusPlatform;
+pub struct NexusPlatform<H = IdentityOutput>(PhantomData<H>);
 
-impl Platform for NexusPlatform {
+impl<H: OutputHasher> Platform for NexusPlatform<H> {
     fn read_whole_input() -> Vec<u8> {
         nexus_rt::read_private_input().unwrap()
     }
 
     fn write_whole_output(output: &[u8]) {
-        nexus_rt::write_public_output(&output).unwrap()
+        let hash = H::output_hash(output);
+        nexus_rt::write_public_output(&*hash).unwrap()
     }
 }
diff --git a/crates/zkvm/openvm/platform/Cargo.toml b/crates/zkvm/openvm/platform/Cargo.toml
index ffcb0b5..f567f84 100644
--- a/crates/zkvm/openvm/platform/Cargo.toml
+++ b/crates/zkvm/openvm/platform/Cargo.toml
@@ -10,7 +10,7 @@ license.workspace = true
 openvm.workspace = true
 
 # Local dependencies
-ere-platform-trait = { workspace = true, features = ["output-hasher"] }
+ere-platform-trait.workspace = true
 
 [features]
 default = ["getrandom-unsupported"]
diff --git a/crates/zkvm/openvm/platform/src/lib.rs b/crates/zkvm/openvm/platform/src/lib.rs
index 1878891..a39ff5a 100644
--- a/crates/zkvm/openvm/platform/src/lib.rs
+++ b/crates/zkvm/openvm/platform/src/lib.rs
@@ -3,24 +3,24 @@
 extern crate alloc;
 
 use alloc::vec::Vec;
-use core::marker::PhantomData;
-use ere_platform_trait::output_hasher::{OutputHasher, digest::typenum::U32};
+use core::{marker::PhantomData, ops::Deref};
+use ere_platform_trait::output_hasher::FixedOutputHasher;
 
 pub use ere_platform_trait::{
     Platform,
-    output_hasher::{IdentityOutput, PaddedOutput},
+    output_hasher::{IdentityOutput, PaddedOutput, digest::typenum::U32},
 };
 pub use openvm;
 
-pub struct OpenVMPlatform<D>(PhantomData<D>);
+pub struct OpenVMPlatform<H>(PhantomData<H>);
 
-impl<D: OutputHasher<OutputSize = U32>> Platform for OpenVMPlatform<D> {
+impl<H: FixedOutputHasher<OutputSize = U32>> Platform for OpenVMPlatform<H> {
     fn read_whole_input() -> Vec<u8> {
         openvm::io::read_vec()
     }
 
     fn write_whole_output(output: &[u8]) {
-        let hash = D::output_hash(output);
-        openvm::io::reveal_bytes32(hash.into());
+        let hash = H::output_hash(output).deref().try_into().unwrap();
+        openvm::io::reveal_bytes32(hash);
     }
 }
diff --git a/crates/zkvm/pico/platform/src/lib.rs b/crates/zkvm/pico/platform/src/lib.rs
index a57dd6a..43b9c51 100644
--- a/crates/zkvm/pico/platform/src/lib.rs
+++ b/crates/zkvm/pico/platform/src/lib.rs
@@ -3,18 +3,24 @@
 extern crate alloc;
 
 use alloc::vec::Vec;
+use core::marker::PhantomData;
+use ere_platform_trait::output_hasher::OutputHasher;
 
-pub use ere_platform_trait::Platform;
+pub use ere_platform_trait::{
+    Platform,
+    output_hasher::{IdentityOutput, PaddedOutput, digest::typenum},
+};
 pub use pico_sdk;
 
-pub struct PicoPlatform;
+pub struct PicoPlatform<H = IdentityOutput>(PhantomData<H>);
 
-impl Platform for PicoPlatform {
+impl<H: OutputHasher> Platform for PicoPlatform<H> {
     fn read_whole_input() -> Vec<u8> {
         pico_sdk::io::read_vec()
     }
 
     fn write_whole_output(output: &[u8]) {
-        pico_sdk::io::commit_bytes(output);
+        let hash = H::output_hash(output);
+        pico_sdk::io::commit_bytes(&*hash);
     }
 }
diff --git a/crates/zkvm/risc0/platform/src/lib.rs b/crates/zkvm/risc0/platform/src/lib.rs
index 458ec8a..33386f0 100644
--- a/crates/zkvm/risc0/platform/src/lib.rs
+++ b/crates/zkvm/risc0/platform/src/lib.rs
@@ -3,13 +3,18 @@
 extern crate alloc;
 
 use alloc::{vec, vec::Vec};
+use core::marker::PhantomData;
+use ere_platform_trait::output_hasher::OutputHasher;
 
-pub use ere_platform_trait::Platform;
+pub use ere_platform_trait::{
+    Platform,
+    output_hasher::{IdentityOutput, PaddedOutput, digest::typenum},
+};
 pub use risc0_zkvm;
 
-pub struct Risc0Platform;
+pub struct Risc0Platform<H = IdentityOutput>(PhantomData<H>);
 
-impl Platform for Risc0Platform {
+impl<H: OutputHasher> Platform for Risc0Platform<H> {
     fn read_whole_input() -> Vec<u8> {
         let len = {
             let mut bytes = [0; 4];
@@ -22,6 +27,7 @@ impl Platform for Risc0Platform {
     }
 
     fn write_whole_output(output: &[u8]) {
-        risc0_zkvm::guest::env::commit_slice(output);
+        let hash = H::output_hash(output);
+        risc0_zkvm::guest::env::commit_slice(&*hash);
     }
 }
diff --git a/crates/zkvm/sp1/platform/src/lib.rs b/crates/zkvm/sp1/platform/src/lib.rs
index 3cdf5e6..cce618e 100644
--- a/crates/zkvm/sp1/platform/src/lib.rs
+++ b/crates/zkvm/sp1/platform/src/lib.rs
@@ -3,18 +3,24 @@
 extern crate alloc;
 
 use alloc::vec::Vec;
+use core::marker::PhantomData;
+use ere_platform_trait::output_hasher::OutputHasher;
 
-pub use ere_platform_trait::Platform;
+pub use ere_platform_trait::{
+    Platform,
+    output_hasher::{IdentityOutput, PaddedOutput, digest::typenum},
+};
 pub use sp1_zkvm;
 
-pub struct SP1Platform;
+pub struct SP1Platform<H = IdentityOutput>(PhantomData<H>);
 
-impl Platform for SP1Platform {
+impl<H: OutputHasher> Platform for SP1Platform<H> {
     fn read_whole_input() -> Vec<u8> {
         sp1_zkvm::io::read_vec()
     }
 
     fn write_whole_output(output: &[u8]) {
-        sp1_zkvm::io::commit_slice(output);
+        let hash = H::output_hash(output);
+        sp1_zkvm::io::commit_slice(&*hash);
     }
 }
diff --git a/crates/zkvm/ziren/platform/src/lib.rs b/crates/zkvm/ziren/platform/src/lib.rs
index 39e6b37..0dd30ee 100644
--- a/crates/zkvm/ziren/platform/src/lib.rs
+++ b/crates/zkvm/ziren/platform/src/lib.rs
@@ -3,18 +3,24 @@
 extern crate alloc;
 
 use alloc::vec::Vec;
+use core::marker::PhantomData;
+use ere_platform_trait::output_hasher::OutputHasher;
 
-pub use ere_platform_trait::Platform;
+pub use ere_platform_trait::{
+    Platform,
+    output_hasher::{IdentityOutput, PaddedOutput, digest::typenum},
+};
 pub use zkm_zkvm;
 
-pub struct ZirenPlatform;
+pub struct ZirenPlatform<H = IdentityOutput>(PhantomData<H>);
 
-impl Platform for ZirenPlatform {
+impl<H: OutputHasher> Platform for ZirenPlatform<H> {
     fn read_whole_input() -> Vec<u8> {
         zkm_zkvm::io::read_vec()
     }
 
     fn write_whole_output(output: &[u8]) {
-        zkm_zkvm::io::commit_slice(output);
+        let hash = H::output_hash(output);
+        zkm_zkvm::io::commit_slice(&*hash);
     }
 }
diff --git a/crates/zkvm/zisk/platform/Cargo.toml b/crates/zkvm/zisk/platform/Cargo.toml
index 81b6db5..8bb3f86 100644
--- a/crates/zkvm/zisk/platform/Cargo.toml
+++ b/crates/zkvm/zisk/platform/Cargo.toml
@@ -10,7 +10,7 @@ license.workspace = true
 ziskos.workspace = true
 
 # Local dependencies
-ere-platform-trait = { workspace = true, features = ["output-hasher"] }
+ere-platform-trait.workspace = true
 
 [features]
 default = []
diff --git a/crates/zkvm/zisk/platform/src/lib.rs b/crates/zkvm/zisk/platform/src/lib.rs
index 153e09c..0f50900 100644
--- a/crates/zkvm/zisk/platform/src/lib.rs
+++ b/crates/zkvm/zisk/platform/src/lib.rs
@@ -4,23 +4,23 @@ extern crate alloc;
 
 use alloc::vec::Vec;
 use core::marker::PhantomData;
-use ere_platform_trait::output_hasher::{OutputHasher, digest::typenum::U32};
+use ere_platform_trait::output_hasher::FixedOutputHasher;
 
 pub use ere_platform_trait::{
     Platform,
-    output_hasher::{IdentityOutput, PaddedOutput},
+    output_hasher::{IdentityOutput, PaddedOutput, digest::typenum::U32},
 };
 pub use ziskos;
 
-pub struct ZiskPlatform<D>(PhantomData<D>);
+pub struct ZiskPlatform<H>(PhantomData<H>);
 
-impl<D: OutputHasher<OutputSize = U32>> Platform for ZiskPlatform<D> {
+impl<H: FixedOutputHasher<OutputSize = U32>> Platform for ZiskPlatform<H> {
     fn read_whole_input() -> Vec<u8> {
         ziskos::read_input()
     }
 
     fn write_whole_output(output: &[u8]) {
-        let hash = D::output_hash(output);
+        let hash = H::output_hash(output);
         hash.chunks_exact(4).enumerate().for_each(|(idx, bytes)| {
             ziskos::set_output(idx, u32::from_le_bytes(bytes.try_into().unwrap()))
         });
diff --git a/tests/risc0/allocs_alignment/src/main.rs b/tests/risc0/allocs_alignment/src/main.rs
index 3751b41..c2b3d16 100644
--- a/tests/risc0/allocs_alignment/src/main.rs
+++ b/tests/risc0/allocs_alignment/src/main.rs
@@ -1,8 +1,9 @@
 use ere_platform_risc0::{Platform, Risc0Platform};
 
+type P = Risc0Platform;
+
 fn main() {
-    let alignment =
-        u32::from_le_bytes(Risc0Platform::read_whole_input().try_into().unwrap()) as usize;
+    let alignment = u32::from_le_bytes(P::read_whole_input().try_into().unwrap()) as usize;
 
     let layout = std::alloc::Layout::from_size_align(1, alignment).unwrap();
     let ptr = unsafe { std::alloc::alloc(layout) };