diff --git a/Cargo.lock b/Cargo.lock
index 9fbd014..7b62516 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1965,7 +1965,7 @@ checksum = "3779b94aeb87e8bd4e834cee3650289ee9e0d5677f976ecdb6d219e5f4f6cd94"
 dependencies = [
  "rand_chacha 0.9.0",
  "rand_core 0.9.3",
- "zerocopy 0.8.24",
+ "zerocopy 0.8.27",
 ]
 
 [[package]]
@@ -2115,7 +2115,7 @@ dependencies = [
  "thiserror 1.0.69",
  "toml",
  "uds",
- "zerocopy 0.7.35",
+ "zerocopy 0.8.27",
  "zeroize",
 ]
 
@@ -2273,7 +2273,7 @@ dependencies = [
  "tokio",
  "typenum",
  "uds",
- "zerocopy 0.7.35",
+ "zerocopy 0.8.27",
  "zeroize",
 ]
 
@@ -2298,7 +2298,7 @@ dependencies = [
  "thiserror 1.0.69",
  "tokio",
  "wireguard-uapi",
- "zerocopy 0.7.35",
+ "zerocopy 0.8.27",
 ]
 
 [[package]]
@@ -3315,11 +3315,11 @@ dependencies = [
 
 [[package]]
 name = "zerocopy"
-version = "0.8.24"
+version = "0.8.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2586fea28e186957ef732a5f8b3be2da217d65c5969d4b1e17f973ebbe876879"
+checksum = "0894878a5fa3edfd6da3f88c4805f4c8558e2b996227a3d864f47fe11e38282c"
 dependencies = [
- "zerocopy-derive 0.8.24",
+ "zerocopy-derive 0.8.27",
 ]
 
 [[package]]
@@ -3335,9 +3335,9 @@ dependencies = [
 
 [[package]]
 name = "zerocopy-derive"
-version = "0.8.24"
+version = "0.8.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a996a8f63c5c4448cd959ac1bab0aaa3306ccfd060472f85943ee0750f0169be"
+checksum = "88d2b8d9c68ad2b9e4340d7832716a4d21a22a1154777ad56ea55c51a9cf3831"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/Cargo.toml b/Cargo.toml
index d67f659..bcc7802 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -66,7 +66,7 @@ chacha20poly1305 = { version = "0.10.1", default-features = false, features = [
   "std",
   "heapless",
 ] }
-zerocopy = { version = "0.7.35", features = ["derive"] }
+zerocopy = { version = "0.8.27", features = ["derive"] }
 home = "=0.5.9" # 5.11 requires rustc 1.81
 derive_builder = "0.20.1"
 tokio = { version = "1.46", features = ["macros", "rt-multi-thread"] }
diff --git a/rosenpass/Cargo.toml b/rosenpass/Cargo.toml
index 5ac9a30..d424106 100644
--- a/rosenpass/Cargo.toml
+++ b/rosenpass/Cargo.toml
@@ -97,6 +97,7 @@ rustix = { workspace = true }
 serde_json = { workspace = true }
 
 [features]
+default = ["experiment_api"]
 experiment_cookie_dos_mitigation = []
 experiment_memfd_secret = ["rosenpass-wireguard-broker/experiment_memfd_secret"]
 experiment_libcrux_all = ["rosenpass-ciphers/experiment_libcrux_all"]
diff --git a/rosenpass/src/api/api_handler.rs b/rosenpass/src/api/api_handler.rs
index d660926..1d36b41 100644
--- a/rosenpass/src/api/api_handler.rs
+++ b/rosenpass/src/api/api_handler.rs
@@ -316,7 +316,7 @@ where
             use crate::app_server::BrokerStorePtr;
             //
             use rosenpass_secret_memory::Public;
-            use zerocopy::AsBytes;
+            use zerocopy::IntoBytes;
             (self.app_server().brokers.store.len() - 1)
                 .apply(|x| x as u64)
                 .apply(|x| Public::from_slice(x.as_bytes()))
diff --git a/rosenpass/src/api/boilerplate/byte_slice_ext.rs b/rosenpass/src/api/boilerplate/byte_slice_ext.rs
index 283b886..2aae68c 100644
--- a/rosenpass/src/api/boilerplate/byte_slice_ext.rs
+++ b/rosenpass/src/api/boilerplate/byte_slice_ext.rs
@@ -1,4 +1,4 @@
-use zerocopy::{ByteSlice, Ref};
+use zerocopy::{ByteSlice, Ref, SplitByteSlice};
 
 use rosenpass_util::zerocopy::{RefMaker, ZerocopySliceExt};
 
@@ -7,7 +7,7 @@ use super::{
     ResponseMsgType, ResponseRef, SupplyKeypairRequest, SupplyKeypairResponse,
 };
 
-pub trait ByteSliceRefExt: ByteSlice {
+pub trait ByteSliceRefExt: SplitByteSlice {
     /// Shorthand for the typed use of [ZerocopySliceExt::zk_ref_maker].
     fn msg_type_maker(self) -> RefMaker<Self, RawMsgType> {
         self.zk_ref_maker()
@@ -259,4 +259,4 @@ pub trait ByteSliceRefExt: ByteSlice {
     }
 }
 
-impl<B: ByteSlice> ByteSliceRefExt for B {}
+impl<B: SplitByteSlice> ByteSliceRefExt for B {}
diff --git a/rosenpass/src/api/boilerplate/message_trait.rs b/rosenpass/src/api/boilerplate/message_trait.rs
index f25d99f..83b3559 100644
--- a/rosenpass/src/api/boilerplate/message_trait.rs
+++ b/rosenpass/src/api/boilerplate/message_trait.rs
@@ -1,4 +1,4 @@
-use zerocopy::{ByteSliceMut, Ref};
+use zerocopy::{Ref, SplitByteSliceMut};
 
 use rosenpass_util::zerocopy::RefMaker;
 
@@ -35,7 +35,7 @@ pub trait Message {
     /// # Examples
     ///
     /// See [crate::api::PingRequest::setup]
-    fn setup<B: ByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>>;
+    fn setup<B: SplitByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>>;
 }
 
 /// Additional convenience functions for working with [rosenpass_util::zerocopy::RefMaker]
@@ -45,7 +45,7 @@ pub trait ZerocopyResponseMakerSetupMessageExt<B, T> {
 
 impl<B, T> ZerocopyResponseMakerSetupMessageExt<B, T> for RefMaker<B, T>
 where
-    B: ByteSliceMut,
+    B: SplitByteSliceMut,
     T: Message,
 {
     /// Initialize the message using [Message::setup].
diff --git a/rosenpass/src/api/boilerplate/message_type.rs b/rosenpass/src/api/boilerplate/message_type.rs
index ab1ec82..3af645e 100644
--- a/rosenpass/src/api/boilerplate/message_type.rs
+++ b/rosenpass/src/api/boilerplate/message_type.rs
@@ -1,6 +1,6 @@
 use hex_literal::hex;
 use rosenpass_util::zerocopy::RefMaker;
-use zerocopy::ByteSlice;
+use zerocopy::{SplitByteSlice};
 
 use crate::RosenpassError::{self, InvalidApiMessageType};
 
@@ -169,12 +169,12 @@ pub trait RefMakerRawMsgTypeExt {
     fn parse_response_msg_type(self) -> anyhow::Result<ResponseMsgType>;
 }
 
-impl<B: ByteSlice> RefMakerRawMsgTypeExt for RefMaker<B, RawMsgType> {
+impl<B: SplitByteSlice> RefMakerRawMsgTypeExt for RefMaker<B, RawMsgType> {
     fn parse_request_msg_type(self) -> anyhow::Result<RequestMsgType> {
-        Ok(self.parse()?.read().try_into()?)
+        Ok(zerocopy::Ref::read(&self.parse()?).try_into()?)
     }
 
     fn parse_response_msg_type(self) -> anyhow::Result<ResponseMsgType> {
-        Ok(self.parse()?.read().try_into()?)
+        Ok(zerocopy::Ref::<B, u128>::read(&self.parse()?).try_into()?)
     }
 }
diff --git a/rosenpass/src/api/boilerplate/payload.rs b/rosenpass/src/api/boilerplate/payload.rs
index 3f58f70..3598425 100644
--- a/rosenpass/src/api/boilerplate/payload.rs
+++ b/rosenpass/src/api/boilerplate/payload.rs
@@ -1,5 +1,5 @@
 use rosenpass_util::zerocopy::ZerocopyMutSliceExt;
-use zerocopy::{AsBytes, ByteSliceMut, FromBytes, FromZeroes, Ref};
+use zerocopy::{SplitByteSliceMut, FromBytes, Immutable, IntoBytes, KnownLayout, Ref};
 
 use super::{Message, RawMsgType, RequestMsgType, ResponseMsgType};
 
@@ -12,8 +12,8 @@ pub const MAX_REQUEST_FDS: usize = 2;
 
 /// Message envelope for API messages
 #[repr(packed)]
-#[derive(Debug, Copy, Clone, Hash, AsBytes, FromBytes, FromZeroes, PartialEq, Eq)]
-pub struct Envelope<M: AsBytes + FromBytes> {
+#[derive(Debug, Copy, Clone, Hash, IntoBytes, FromBytes, PartialEq, Eq, Immutable, KnownLayout)]
+pub struct Envelope<M: IntoBytes + FromBytes + Immutable + KnownLayout> {
     /// Which message this is
     pub msg_type: RawMsgType,
     /// The actual Paylod
@@ -27,7 +27,7 @@ pub type ResponseEnvelope<M> = Envelope<M>;
 
 #[allow(missing_docs)]
 #[repr(packed)]
-#[derive(Debug, Copy, Clone, Hash, AsBytes, FromBytes, FromZeroes, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, Hash, IntoBytes, FromBytes, PartialEq, Eq, Immutable, KnownLayout)]
 pub struct PingRequestPayload {
     /// Randomly generated connection id
     pub echo: [u8; 256],
@@ -55,7 +55,7 @@ impl Message for PingRequest {
         }
     }
 
-    fn setup<B: ByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>> {
+    fn setup<B: SplitByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>> {
         let mut r: Ref<B, Self> = buf.zk_zeroized()?;
         r.init();
         Ok(r)
@@ -68,7 +68,7 @@ impl Message for PingRequest {
 
 #[allow(missing_docs)]
 #[repr(packed)]
-#[derive(Debug, Copy, Clone, Hash, AsBytes, FromBytes, FromZeroes, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, Hash, IntoBytes, FromBytes, PartialEq, Eq, Immutable, KnownLayout)]
 pub struct PingResponsePayload {
     /// Randomly generated connection id
     pub echo: [u8; 256],
@@ -96,7 +96,7 @@ impl Message for PingResponse {
         }
     }
 
-    fn setup<B: ByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>> {
+    fn setup<B: SplitByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>> {
         let mut r: Ref<B, Self> = buf.zk_zeroized()?;
         r.init();
         Ok(r)
@@ -109,7 +109,7 @@ impl Message for PingResponse {
 
 #[allow(missing_docs)]
 #[repr(packed)]
-#[derive(Debug, Copy, Clone, Hash, AsBytes, FromBytes, FromZeroes, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, Hash, IntoBytes, FromBytes, PartialEq, Eq, Immutable, KnownLayout)]
 pub struct SupplyKeypairRequestPayload {}
 
 #[allow(missing_docs)]
@@ -140,7 +140,7 @@ impl Message for SupplyKeypairRequest {
         }
     }
 
-    fn setup<B: ByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>> {
+    fn setup<B: SplitByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>> {
         let mut r: Ref<B, Self> = buf.zk_zeroized()?;
         r.init();
         Ok(r)
@@ -169,7 +169,7 @@ pub mod supply_keypair_response_status {
 
 #[allow(missing_docs)]
 #[repr(packed)]
-#[derive(Debug, Copy, Clone, Hash, AsBytes, FromBytes, FromZeroes, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, Hash, IntoBytes, FromBytes, PartialEq, Eq, Immutable, KnownLayout)]
 pub struct SupplyKeypairResponsePayload {
     #[allow(missing_docs)]
     pub status: u128,
@@ -197,7 +197,7 @@ impl Message for SupplyKeypairResponse {
         }
     }
 
-    fn setup<B: ByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>> {
+    fn setup<B: SplitByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>> {
         let mut r: Ref<B, Self> = buf.zk_zeroized()?;
         r.init();
         Ok(r)
@@ -210,7 +210,7 @@ impl Message for SupplyKeypairResponse {
 
 #[allow(missing_docs)]
 #[repr(packed)]
-#[derive(Debug, Copy, Clone, Hash, AsBytes, FromBytes, FromZeroes, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, Hash, IntoBytes, FromBytes, PartialEq, Eq, Immutable, KnownLayout)]
 pub struct AddListenSocketRequestPayload {}
 
 #[allow(missing_docs)]
@@ -241,7 +241,7 @@ impl Message for AddListenSocketRequest {
         }
     }
 
-    fn setup<B: ByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>> {
+    fn setup<B: SplitByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>> {
         let mut r: Ref<B, Self> = buf.zk_zeroized()?;
         r.init();
         Ok(r)
@@ -264,7 +264,7 @@ pub mod add_listen_socket_response_status {
 
 #[allow(missing_docs)]
 #[repr(packed)]
-#[derive(Debug, Copy, Clone, Hash, AsBytes, FromBytes, FromZeroes, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, Hash, IntoBytes, FromBytes, PartialEq, Eq, Immutable, KnownLayout)]
 pub struct AddListenSocketResponsePayload {
     pub status: u128,
 }
@@ -291,7 +291,7 @@ impl Message for AddListenSocketResponse {
         }
     }
 
-    fn setup<B: ByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>> {
+    fn setup<B: SplitByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>> {
         let mut r: Ref<B, Self> = buf.zk_zeroized()?;
         r.init();
         Ok(r)
@@ -304,7 +304,7 @@ impl Message for AddListenSocketResponse {
 
 #[allow(missing_docs)]
 #[repr(packed)]
-#[derive(Debug, Copy, Clone, Hash, AsBytes, FromBytes, FromZeroes, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, Hash, IntoBytes, FromBytes, PartialEq, Eq, Immutable, KnownLayout)]
 pub struct AddPskBrokerRequestPayload {}
 
 #[allow(missing_docs)]
@@ -336,7 +336,7 @@ impl Message for AddPskBrokerRequest {
         }
     }
 
-    fn setup<B: ByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>> {
+    fn setup<B: SplitByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>> {
         let mut r: Ref<B, Self> = buf.zk_zeroized()?;
         r.init();
         Ok(r)
@@ -359,7 +359,7 @@ pub mod add_psk_broker_response_status {
 
 #[allow(missing_docs)]
 #[repr(packed)]
-#[derive(Debug, Copy, Clone, Hash, AsBytes, FromBytes, FromZeroes, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, Hash, IntoBytes, FromBytes, PartialEq, Eq, Immutable, KnownLayout)]
 pub struct AddPskBrokerResponsePayload {
     pub status: u128,
 }
@@ -386,7 +386,7 @@ impl Message for AddPskBrokerResponse {
         }
     }
 
-    fn setup<B: ByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>> {
+    fn setup<B: SplitByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self>> {
         let mut r: Ref<B, Self> = buf.zk_zeroized()?;
         r.init();
         Ok(r)
diff --git a/rosenpass/src/api/boilerplate/request_ref.rs b/rosenpass/src/api/boilerplate/request_ref.rs
index f988940..969192a 100644
--- a/rosenpass/src/api/boilerplate/request_ref.rs
+++ b/rosenpass/src/api/boilerplate/request_ref.rs
@@ -1,6 +1,6 @@
-use anyhow::ensure;
+use anyhow::{anyhow, ensure};
 
-use zerocopy::{ByteSlice, ByteSliceMut, Ref};
+use zerocopy::{IntoBytes, Ref, SplitByteSlice, SplitByteSliceMut};
 
 use super::{ByteSliceRefExt, MessageAttributes, PingRequest, RequestMsgType};
 
@@ -13,7 +13,7 @@ struct RequestRefMaker<B> {
     msg_type: RequestMsgType,
 }
 
-impl<B: ByteSlice> RequestRef<B> {
+impl<B: SplitByteSlice> RequestRef<B> {
     /// Produce a [RequestRef] from a raw message buffer,
     /// reading the type from the buffer
     ///
@@ -95,7 +95,7 @@ impl<B> From<Ref<B, super::AddPskBrokerRequest>> for RequestRef<B> {
     }
 }
 
-impl<B: ByteSlice> RequestRefMaker<B> {
+impl<B: SplitByteSlice> RequestRefMaker<B> {
     fn new(buf: B) -> anyhow::Result<Self> {
         let msg_type = buf.deref().request_msg_type_from_prefix()?;
         Ok(Self { buf, msg_type })
@@ -125,7 +125,8 @@ impl<B: ByteSlice> RequestRefMaker<B> {
         self.ensure_fit()?;
         let point = self.target_size();
         let Self { buf, msg_type } = self;
-        let (buf, _) = buf.split_at(point);
+        let (buf, _) = buf.split_at(point)
+            .map_err(|_| anyhow!("Failed to split buffer"))?;
         Ok(Self { buf, msg_type })
     }
 
@@ -134,7 +135,8 @@ impl<B: ByteSlice> RequestRefMaker<B> {
         self.ensure_fit()?;
         let point = self.buf.len() - self.target_size();
         let Self { buf, msg_type } = self;
-        let (buf, _) = buf.split_at(point);
+        let (buf, _) = buf.split_at(point)
+            .map_err(|_| anyhow!("Failed to split buffer"))?;
         Ok(Self { buf, msg_type })
     }
 
@@ -159,7 +161,7 @@ pub enum RequestRef<B> {
 
 impl<B> RequestRef<B>
 where
-    B: ByteSlice,
+    B: SplitByteSlice,
 {
     /// Access the byte data of this reference
     ///
@@ -168,25 +170,25 @@ where
     /// See [Self::parse].
     pub fn bytes(&self) -> &[u8] {
         match self {
-            Self::Ping(r) => r.bytes(),
-            Self::SupplyKeypair(r) => r.bytes(),
-            Self::AddListenSocket(r) => r.bytes(),
-            Self::AddPskBroker(r) => r.bytes(),
+            Self::Ping(r) => r.as_bytes(),
+            Self::SupplyKeypair(r) => r.as_bytes(),
+            Self::AddListenSocket(r) => r.as_bytes(),
+            Self::AddPskBroker(r) => r.as_bytes(),
         }
     }
 }
 
 impl<B> RequestRef<B>
 where
-    B: ByteSliceMut,
+    B: SplitByteSliceMut,
 {
     /// Access the byte data of this reference; mutably
     pub fn bytes_mut(&mut self) -> &[u8] {
         match self {
-            Self::Ping(r) => r.bytes_mut(),
-            Self::SupplyKeypair(r) => r.bytes_mut(),
-            Self::AddListenSocket(r) => r.bytes_mut(),
-            Self::AddPskBroker(r) => r.bytes_mut(),
+            Self::Ping(r) => r.as_mut_bytes(),
+            Self::SupplyKeypair(r) => r.as_mut_bytes(),
+            Self::AddListenSocket(r) => r.as_mut_bytes(),
+            Self::AddPskBroker(r) => r.as_mut_bytes(),
         }
     }
 }
diff --git a/rosenpass/src/api/boilerplate/request_response.rs b/rosenpass/src/api/boilerplate/request_response.rs
index 17f7596..9afce28 100644
--- a/rosenpass/src/api/boilerplate/request_response.rs
+++ b/rosenpass/src/api/boilerplate/request_response.rs
@@ -1,7 +1,7 @@
 use rosenpass_util::zerocopy::{
     RefMaker, ZerocopyEmancipateExt, ZerocopyEmancipateMutExt, ZerocopySliceExt,
 };
-use zerocopy::{ByteSlice, ByteSliceMut, Ref};
+use zerocopy::{Immutable, KnownLayout, Ref, SplitByteSlice, SplitByteSliceMut};
 
 use super::{Message, PingRequest, PingResponse};
 use super::{RequestRef, ResponseRef, ZerocopyResponseMakerSetupMessageExt};
@@ -9,27 +9,27 @@ use super::{RequestRef, ResponseRef, ZerocopyResponseMakerSetupMessageExt};
 /// Extension trait for [Message]s that are requests messages
 pub trait RequestMsg: Sized + Message {
     /// The response message belonging to this request message
-    type ResponseMsg: ResponseMsg;
+    type ResponseMsg: ResponseMsg + Immutable + KnownLayout;
 
     /// Construct a response make for this particular message
-    fn zk_response_maker<B: ByteSlice>(buf: B) -> RefMaker<B, Self::ResponseMsg> {
+    fn zk_response_maker<B: SplitByteSlice>(buf: B) -> RefMaker<B, Self::ResponseMsg> {
         buf.zk_ref_maker()
     }
 
     /// Setup a response maker (through [Message::setup]) for this request message type
-    fn setup_response<B: ByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self::ResponseMsg>> {
+    fn setup_response<B: SplitByteSliceMut>(buf: B) -> anyhow::Result<Ref<B, Self::ResponseMsg>> {
         Self::zk_response_maker(buf).setup_msg()
     }
 
     /// Setup a response maker from a buffer prefix (through [Message::setup]) for this request message type
-    fn setup_response_from_prefix<B: ByteSliceMut>(
+    fn setup_response_from_prefix<B: SplitByteSliceMut>(
         buf: B,
     ) -> anyhow::Result<Ref<B, Self::ResponseMsg>> {
         Self::zk_response_maker(buf).from_prefix()?.setup_msg()
     }
 
     /// Setup a response maker from a buffer suffix (through [Message::setup]) for this request message type
-    fn setup_response_from_suffix<B: ByteSliceMut>(
+    fn setup_response_from_suffix<B: SplitByteSliceMut>(
         buf: B,
     ) -> anyhow::Result<Ref<B, Self::ResponseMsg>> {
         Self::zk_response_maker(buf).from_prefix()?.setup_msg()
@@ -125,8 +125,8 @@ impl<B1, B2> From<AddPskBrokerPair<B1, B2>> for RequestResponsePair<B1, B2> {
 
 impl<B1, B2> RequestResponsePair<B1, B2>
 where
-    B1: ByteSlice,
-    B2: ByteSlice,
+    B1: SplitByteSlice,
+    B2: SplitByteSlice,
 {
     /// Returns a tuple to both the request and the response message
     pub fn both(&self) -> (RequestRef<&[u8]>, ResponseRef<&[u8]>) {
@@ -167,8 +167,8 @@ where
 
 impl<B1, B2> RequestResponsePair<B1, B2>
 where
-    B1: ByteSliceMut,
-    B2: ByteSliceMut,
+    B1: SplitByteSliceMut,
+    B2: SplitByteSliceMut,
 {
     /// Returns a mutable tuple to both the request and the response message
     pub fn both_mut(&mut self) -> (RequestRef<&mut [u8]>, ResponseRef<&mut [u8]>) {
diff --git a/rosenpass/src/api/boilerplate/response_ref.rs b/rosenpass/src/api/boilerplate/response_ref.rs
index 3b9fc19..7fc4270 100644
--- a/rosenpass/src/api/boilerplate/response_ref.rs
+++ b/rosenpass/src/api/boilerplate/response_ref.rs
@@ -1,7 +1,7 @@
 // TODO: This is copied verbatim from ResponseRef…not pretty
-use anyhow::ensure;
+use anyhow::{anyhow, ensure};
 
-use zerocopy::{ByteSlice, ByteSliceMut, Ref};
+use zerocopy::{IntoBytes, Ref, SplitByteSlice, SplitByteSliceMut};
 
 use super::{ByteSliceRefExt, MessageAttributes, PingResponse, ResponseMsgType};
 
@@ -16,7 +16,7 @@ struct ResponseRefMaker<B> {
     msg_type: ResponseMsgType,
 }
 
-impl<B: ByteSlice> ResponseRef<B> {
+impl<B: SplitByteSlice> ResponseRef<B> {
     /// Produce a [ResponseRef] from a raw message buffer,
     /// reading the type from the buffer
     ///
@@ -99,7 +99,7 @@ impl<B> From<Ref<B, super::AddPskBrokerResponse>> for ResponseRef<B> {
     }
 }
 
-impl<B: ByteSlice> ResponseRefMaker<B> {
+impl<B: SplitByteSlice> ResponseRefMaker<B> {
     fn new(buf: B) -> anyhow::Result<Self> {
         let msg_type = buf.deref().response_msg_type_from_prefix()?;
         Ok(Self { buf, msg_type })
@@ -129,7 +129,8 @@ impl<B: ByteSlice> ResponseRefMaker<B> {
         self.ensure_fit()?;
         let point = self.target_size();
         let Self { buf, msg_type } = self;
-        let (buf, _) = buf.split_at(point);
+        let (buf, _) = buf.split_at(point)
+            .map_err(|_| anyhow!("Failed to split buffer!"))?;
         Ok(Self { buf, msg_type })
     }
 
@@ -138,7 +139,8 @@ impl<B: ByteSlice> ResponseRefMaker<B> {
         self.ensure_fit()?;
         let point = self.buf.len() - self.target_size();
         let Self { buf, msg_type } = self;
-        let (buf, _) = buf.split_at(point);
+        let (buf, _) = buf.split_at(point)
+            .map_err(|_| anyhow!("Failed to split buffer!"))?;
         Ok(Self { buf, msg_type })
     }
 
@@ -163,7 +165,7 @@ pub enum ResponseRef<B> {
 
 impl<B> ResponseRef<B>
 where
-    B: ByteSlice,
+    B: SplitByteSlice,
 {
     /// Access the byte data of this reference
     ///
@@ -172,25 +174,25 @@ where
     /// See [Self::parse].
     pub fn bytes(&self) -> &[u8] {
         match self {
-            Self::Ping(r) => r.bytes(),
-            Self::SupplyKeypair(r) => r.bytes(),
-            Self::AddListenSocket(r) => r.bytes(),
-            Self::AddPskBroker(r) => r.bytes(),
+            Self::Ping(r) => r.as_bytes(),
+            Self::SupplyKeypair(r) => r.as_bytes(),
+            Self::AddListenSocket(r) => r.as_bytes(),
+            Self::AddPskBroker(r) => r.as_bytes(),
         }
     }
 }
 
 impl<B> ResponseRef<B>
 where
-    B: ByteSliceMut,
+    B: SplitByteSliceMut,
 {
     /// Access the byte data of this reference; mutably
     pub fn bytes_mut(&mut self) -> &[u8] {
         match self {
-            Self::Ping(r) => r.bytes_mut(),
-            Self::SupplyKeypair(r) => r.bytes_mut(),
-            Self::AddListenSocket(r) => r.bytes_mut(),
-            Self::AddPskBroker(r) => r.bytes_mut(),
+            Self::Ping(r) => r.as_mut_bytes(),
+            Self::SupplyKeypair(r) => r.as_mut_bytes(),
+            Self::AddListenSocket(r) => r.as_mut_bytes(),
+            Self::AddPskBroker(r) => r.as_mut_bytes(),
         }
     }
 }
diff --git a/rosenpass/src/api/boilerplate/server.rs b/rosenpass/src/api/boilerplate/server.rs
index 72a2461..630f498 100644
--- a/rosenpass/src/api/boilerplate/server.rs
+++ b/rosenpass/src/api/boilerplate/server.rs
@@ -1,6 +1,6 @@
 use super::{ByteSliceRefExt, Message, PingRequest, PingResponse, RequestRef, RequestResponsePair};
 use std::{collections::VecDeque, os::fd::OwnedFd};
-use zerocopy::{ByteSlice, ByteSliceMut};
+use zerocopy::{SplitByteSlice, SplitByteSliceMut};
 
 /// The rosenpass API implementation functions.
 ///
@@ -152,8 +152,8 @@ pub trait Server {
         req_fds: &mut VecDeque<OwnedFd>,
     ) -> anyhow::Result<()>
     where
-        ReqBuf: ByteSlice,
-        ResBuf: ByteSliceMut,
+        ReqBuf: SplitByteSlice,
+        ResBuf: SplitByteSliceMut,
     {
         match p {
             RequestResponsePair::Ping((req, res)) => self.ping(req, req_fds, res),
@@ -182,8 +182,8 @@ pub trait Server {
         res: ResBuf,
     ) -> anyhow::Result<usize>
     where
-        ReqBuf: ByteSlice,
-        ResBuf: ByteSliceMut,
+        ReqBuf: SplitByteSlice,
+        ResBuf: SplitByteSliceMut,
     {
         let req = req.parse_request_from_prefix()?;
         // TODO: This is not pretty; This match should be moved into RequestRef
diff --git a/rosenpass/src/app_server.rs b/rosenpass/src/app_server.rs
index eeff163..de3684e 100644
--- a/rosenpass/src/app_server.rs
+++ b/rosenpass/src/app_server.rs
@@ -13,7 +13,7 @@ use signal_hook_mio::v1_0 as signal_hook_mio;
 use anyhow::{bail, Context, Result};
 use derive_builder::Builder;
 use log::{error, info, warn};
-use zerocopy::AsBytes;
+use zerocopy::IntoBytes;
 
 use rosenpass_util::attempt;
 use rosenpass_util::fmt::debug::NullDebug;
diff --git a/rosenpass/src/msgs.rs b/rosenpass/src/msgs.rs
index 9fbeba2..21b1c36 100644
--- a/rosenpass/src/msgs.rs
+++ b/rosenpass/src/msgs.rs
@@ -9,7 +9,7 @@
 //! To achieve this we utilize the zerocopy library.
 //!
 use std::mem::size_of;
-use zerocopy::{AsBytes, FromBytes, FromZeroes};
+use zerocopy::{FromBytes, Immutable, IntoBytes, KnownLayout};
 
 use super::RosenpassError;
 use rosenpass_cipher_traits::primitives::{Aead as _, Kem};
@@ -51,7 +51,7 @@ pub type MsgEnvelopeCookie = [u8; COOKIE_SIZE];
 ///
 /// ```
 /// use rosenpass::msgs::{Envelope, InitHello};
-/// use zerocopy::{AsBytes, FromBytes, Ref, FromZeroes};
+/// use zerocopy::{IntoBytes, FromBytes, Ref};
 /// use memoffset::offset_of;
 ///
 /// // Zero-initialization
@@ -76,8 +76,8 @@ pub type MsgEnvelopeCookie = [u8; COOKIE_SIZE];
 /// assert_eq!(ih3.msg_type, 42);
 /// ```
 #[repr(packed)]
-#[derive(AsBytes, FromBytes, FromZeroes, Clone)]
-pub struct Envelope<M: AsBytes + FromBytes> {
+#[derive(IntoBytes, FromBytes, Clone, Immutable, KnownLayout)]
+pub struct Envelope<M: IntoBytes + FromBytes> {
     /// [MsgType] of this message
     pub msg_type: u8,
     /// Reserved for future use
@@ -106,7 +106,7 @@ pub struct Envelope<M: AsBytes + FromBytes> {
 ///
 /// ```
 /// use rosenpass::msgs::{Envelope, InitHello};
-/// use zerocopy::{AsBytes, FromBytes, Ref, FromZeroes};
+/// use zerocopy::{IntoBytes, FromBytes, Ref};
 /// use memoffset::span_of;
 ///
 /// // Zero initialization
@@ -126,7 +126,7 @@ pub struct Envelope<M: AsBytes + FromBytes> {
 /// assert_eq!(ih.payload.sidi, [1,2,3,4]);
 /// ```
 #[repr(packed)]
-#[derive(AsBytes, FromBytes, FromZeroes)]
+#[derive(IntoBytes, FromBytes, Immutable, KnownLayout)]
 pub struct InitHello {
     /// Randomly generated connection id
     pub sidi: [u8; 4],
@@ -155,7 +155,7 @@ pub struct InitHello {
 ///
 /// ```
 /// use rosenpass::msgs::{Envelope, RespHello};
-/// use zerocopy::{AsBytes, FromBytes, Ref, FromZeroes};
+/// use zerocopy::{IntoBytes, FromBytes, Ref};
 /// use memoffset::span_of;
 ///
 /// // Zero initialization
@@ -175,7 +175,7 @@ pub struct InitHello {
 /// assert_eq!(ih.payload.sidi, [1,2,3,4]);
 /// ```
 #[repr(packed)]
-#[derive(AsBytes, FromBytes, FromZeroes)]
+#[derive(IntoBytes, FromBytes, Immutable, KnownLayout)]
 pub struct RespHello {
     /// Randomly generated connection id
     pub sidr: [u8; 4],
@@ -206,7 +206,7 @@ pub struct RespHello {
 ///
 /// ```
 /// use rosenpass::msgs::{Envelope, InitConf};
-/// use zerocopy::{AsBytes, FromBytes, Ref, FromZeroes};
+/// use zerocopy::{IntoBytes, FromBytes, Ref};
 /// use memoffset::span_of;
 ///
 /// // Zero initialization
@@ -226,7 +226,7 @@ pub struct RespHello {
 /// assert_eq!(ih.payload.sidi, [1,2,3,4]);
 /// ```
 #[repr(packed)]
-#[derive(AsBytes, FromBytes, FromZeroes, Debug)]
+#[derive(IntoBytes, FromBytes, Debug, Immutable, KnownLayout)]
 pub struct InitConf {
     /// Copied from InitHello
     pub sidi: [u8; 4],
@@ -264,7 +264,7 @@ pub struct InitConf {
 ///
 /// ```
 /// use rosenpass::msgs::{Envelope, EmptyData};
-/// use zerocopy::{AsBytes, FromBytes, Ref, FromZeroes};
+/// use zerocopy::{IntoBytes, FromBytes, Ref};
 /// use memoffset::span_of;
 ///
 /// // Zero initialization
@@ -284,7 +284,7 @@ pub struct InitConf {
 /// assert_eq!(ih.payload.sid, [1,2,3,4]);
 /// ```
 #[repr(packed)]
-#[derive(AsBytes, FromBytes, FromZeroes, Clone, Copy)]
+#[derive(IntoBytes, FromBytes, Clone, Copy, Immutable, KnownLayout)]
 pub struct EmptyData {
     /// Copied from RespHello
     pub sid: [u8; 4],
@@ -311,7 +311,7 @@ pub struct EmptyData {
 ///
 /// [Envelope] and [InitHello] contain some extra examples on how to use structures from the [::zerocopy] crate.
 #[repr(packed)]
-#[derive(AsBytes, FromBytes, FromZeroes)]
+#[derive(IntoBytes, FromBytes, Immutable, KnownLayout)]
 pub struct Biscuit {
     /// H(spki) – Ident ifies the initiator
     pub pidi: [u8; KEY_LEN],
@@ -336,7 +336,7 @@ pub struct Biscuit {
 ///
 /// [Envelope] and [InitHello] contain some extra examples on how to use structures from the [::zerocopy] crate.
 #[repr(packed)]
-#[derive(AsBytes, FromBytes, FromZeroes)]
+#[derive(IntoBytes, FromBytes, Immutable, KnownLayout)]
 pub struct CookieReplyInner {
     /// [MsgType] of this message
     pub msg_type: u8,
@@ -363,7 +363,7 @@ pub struct CookieReplyInner {
 ///
 /// [Envelope] and [InitHello] contain some extra examples on how to use structures from the [::zerocopy] crate.
 #[repr(packed)]
-#[derive(AsBytes, FromBytes, FromZeroes)]
+#[derive(IntoBytes, FromBytes, Immutable, KnownLayout)]
 pub struct CookieReply {
     pub inner: CookieReplyInner,
     pub padding: [u8; size_of::<Envelope<InitHello>>() - size_of::<CookieReplyInner>()],
diff --git a/rosenpass/src/protocol/protocol.rs b/rosenpass/src/protocol/protocol.rs
index faaa056..c1185ce 100644
--- a/rosenpass/src/protocol/protocol.rs
+++ b/rosenpass/src/protocol/protocol.rs
@@ -17,7 +17,7 @@ use std::{
 use anyhow::{bail, ensure, Context, Result};
 use assert_tv::{TestVector, TestVectorNOP};
 use memoffset::span_of;
-use zerocopy::{AsBytes, FromBytes, Ref};
+use zerocopy::{FromBytes, Immutable, IntoBytes, KnownLayout, Ref};
 
 use rosenpass_cipher_traits::primitives::{
     Aead as _, AeadWithNonceInCiphertext, Kem, KeyedHashInstance,
@@ -413,7 +413,7 @@ pub struct InitiatorHandshake {
 ///
 /// Used as [KnownInitConfResponse] for now cache [EmptyData] (responder confirmation)
 /// responses to [InitConf]
-pub struct KnownResponse<ResponseType: AsBytes + FromBytes> {
+pub struct KnownResponse<ResponseType: IntoBytes + FromBytes> {
     /// When the response was initially computed
     pub received_at: Timing,
     /// Hash of the message that triggered the response; created using
@@ -423,7 +423,7 @@ pub struct KnownResponse<ResponseType: AsBytes + FromBytes> {
     pub response: Envelope<ResponseType>,
 }
 
-impl<ResponseType: AsBytes + FromBytes> Debug for KnownResponse<ResponseType> {
+impl<ResponseType: IntoBytes + FromBytes> Debug for KnownResponse<ResponseType> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("KnownResponse")
             .field("received_at", &self.received_at)
@@ -435,7 +435,7 @@ impl<ResponseType: AsBytes + FromBytes> Debug for KnownResponse<ResponseType> {
 
 #[test]
 fn known_response_format() {
-    use zerocopy::FromZeroes;
+    use zerocopy::FromZeros;
 
     let v = KnownResponse::<[u8; 32]> {
         received_at: 42.0,
@@ -508,7 +508,7 @@ impl KnownResponseHasher {
     /// # Panic & Safety
     ///
     /// Panics in case of a problem with this underlying hash function
-    pub fn hash<Msg: AsBytes + FromBytes>(&self, msg: &Envelope<Msg>) -> KnownResponseHash {
+    pub fn hash<Msg: IntoBytes + FromBytes + Immutable>(&self, msg: &Envelope<Msg>) -> KnownResponseHash {
         let data = &msg.as_bytes()[span_of!(Envelope<Msg>, msg_type..cookie)];
         // This function is only used internally and results are not propagated
         // to outside the peer. Thus, it uses SHAKE256 exclusively.
@@ -2354,8 +2354,8 @@ impl CryptoServer {
     ///
     /// To save some code, the function returns the size of the message,
     /// but the same could be easily achieved by calling [size_of] with the
-    /// message type or by calling [AsBytes::as_bytes] on the message reference.
-    pub fn seal_and_commit_msg<M: AsBytes + FromBytes>(
+    /// message type or by calling [IntoBytes::as_bytes] on the message reference.
+    pub fn seal_and_commit_msg<M: IntoBytes + FromBytes + Immutable + KnownLayout>(
         &mut self,
         peer: PeerPtr,
         msg_type: MsgType,
@@ -3078,7 +3078,7 @@ impl IniHsPtr {
 
 impl<M> Envelope<M>
 where
-    M: AsBytes + FromBytes,
+    M: IntoBytes + FromBytes + Immutable + KnownLayout,
 {
     /// Internal business logic: Calculate the message authentication code (`mac`) and also append cookie value
     pub fn seal(&mut self, peer: PeerPtr, srv: &CryptoServer) -> Result<()> {
@@ -3107,7 +3107,7 @@ where
 
 impl<M> Envelope<M>
 where
-    M: AsBytes + FromBytes,
+    M: IntoBytes + FromBytes + Immutable + KnownLayout,
 {
     /// Internal business logic: Check the message authentication code produced by [Self::seal]
     pub fn check_seal(&self, srv: &CryptoServer, shake_or_blake: KeyedHash) -> Result<bool> {
diff --git a/rosenpass/src/protocol/zerocopy.rs b/rosenpass/src/protocol/zerocopy.rs
index 3e8639b..7d8bf66 100644
--- a/rosenpass/src/protocol/zerocopy.rs
+++ b/rosenpass/src/protocol/zerocopy.rs
@@ -2,19 +2,19 @@
 
 use std::mem::size_of;
 
-use zerocopy::{FromBytes, Ref};
+use zerocopy::{FromBytes, Immutable, KnownLayout, Ref};
 
 use crate::RosenpassError;
 
 /// Used to parse a network message using [zerocopy]
-pub fn truncating_cast_into<T: FromBytes>(
+pub fn truncating_cast_into<T: FromBytes + KnownLayout + Immutable>(
     buf: &mut [u8],
 ) -> Result<Ref<&mut [u8], T>, RosenpassError> {
     Ref::new(&mut buf[..size_of::<T>()]).ok_or(RosenpassError::BufferSizeMismatch)
 }
 
 /// Used to parse a network message using [zerocopy], mutably
-pub fn truncating_cast_into_nomut<T: FromBytes>(
+pub fn truncating_cast_into_nomut<T: FromBytes + KnownLayout + Immutable>(
     buf: &[u8],
 ) -> Result<Ref<&[u8], T>, RosenpassError> {
     Ref::new(&buf[..size_of::<T>()]).ok_or(RosenpassError::BufferSizeMismatch)
diff --git a/util/src/ipc/shm/ringbuf/main.rs b/util/src/ipc/shm/ringbuf/main.rs
index 0ee105e..b62fff4 100644
--- a/util/src/ipc/shm/ringbuf/main.rs
+++ b/util/src/ipc/shm/ringbuf/main.rs
@@ -2,6 +2,8 @@
 
 use std::{borrow::Borrow, sync::atomic::AtomicU64};
 
+use zerocopy::{FromBytes, IntoBytes};
+
 use crate::{
     ipc::shm::SharedMemorySegment,
     ringbuf::concurrent::framework::{
@@ -13,7 +15,8 @@ use crate::{
 ///
 /// These values must be shared between the reader/writer in such a way that access to the inner
 /// variables is synchronized and atomic between the two parties.
-#[derive(Debug, Default)]
+#[repr(C)]
+#[derive(Debug, Default, IntoBytes, FromBytes)]
 pub struct ShmPipeVariables {
     /// See [crate::ringbuf::sched::RingBufferScheduler::items_read()]
     pub items_read: AtomicU64,
diff --git a/util/src/zerocopy/ref_maker.rs b/util/src/zerocopy/ref_maker.rs
index f0c46ed..ffebf3e 100644
--- a/util/src/zerocopy/ref_maker.rs
+++ b/util/src/zerocopy/ref_maker.rs
@@ -1,9 +1,9 @@
 //! A module providing the [`RefMaker`] type and its associated methods for constructing
 //! [`zerocopy::Ref`] references from byte buffers.
 
-use anyhow::{ensure, Context};
+use anyhow::ensure;
 use std::marker::PhantomData;
-use zerocopy::{ByteSlice, ByteSliceMut, Ref};
+use zerocopy::{Immutable, KnownLayout, Ref, SplitByteSlice, SplitByteSliceMut};
 use zeroize::Zeroize;
 
 use crate::zeroize::ZeroizedExt;
@@ -82,7 +82,10 @@ impl<B, T> RefMaker<B, T> {
     }
 }
 
-impl<B: ByteSlice, T> RefMaker<B, T> {
+impl<B: SplitByteSlice, T> RefMaker<B, T>
+where
+    T: KnownLayout + Immutable,
+{
     /// Parses the buffer into a [`zerocopy::Ref<B, T>`].
     ///
     /// This will fail if the buffer is smaller than `size_of::<T>`.
@@ -120,7 +123,7 @@ impl<B: ByteSlice, T> RefMaker<B, T> {
     /// ```
     pub fn parse(self) -> anyhow::Result<Ref<B, T>> {
         self.ensure_fit()?;
-        Ref::<B, T>::new(self.buf).context("Parser error!")
+        Ref::<B, T>::from_bytes(self.buf).map_err(|e| anyhow::anyhow!("Parser error: {e:?}"))
     }
 
     /// Splits the internal buffer into a `RefMaker` containing a buffer with
@@ -142,7 +145,10 @@ impl<B: ByteSlice, T> RefMaker<B, T> {
     /// ```
     pub fn from_prefix_with_tail(self) -> anyhow::Result<(Self, B)> {
         self.ensure_fit()?;
-        let (head, tail) = self.buf.split_at(Self::target_size());
+        let (head, tail) = self
+            .buf
+            .split_at(Self::target_size())
+            .map_err(|_| anyhow::anyhow!("Failed to split buffer!"))?;
         Ok((Self::new(head), tail))
     }
 
@@ -165,7 +171,10 @@ impl<B: ByteSlice, T> RefMaker<B, T> {
     /// ```
     pub fn split_prefix(self) -> anyhow::Result<(Self, Self)> {
         self.ensure_fit()?;
-        let (head, tail) = self.buf.split_at(Self::target_size());
+        let (head, tail) = self
+            .buf
+            .split_at(Self::target_size())
+            .map_err(|_| anyhow::anyhow!("Failed to split buffer!"))?;
         Ok((Self::new(head), Self::new(tail)))
     }
 
@@ -204,7 +213,10 @@ impl<B: ByteSlice, T> RefMaker<B, T> {
     pub fn from_suffix_with_head(self) -> anyhow::Result<(Self, B)> {
         self.ensure_fit()?;
         let point = self.bytes().len() - Self::target_size();
-        let (head, tail) = self.buf.split_at(point);
+        let (head, tail) = self
+            .buf
+            .split_at(point)
+            .map_err(|_| anyhow::anyhow!("Failed to split buffer!"))?;
         Ok((Self::new(tail), head))
     }
 
@@ -227,7 +239,10 @@ impl<B: ByteSlice, T> RefMaker<B, T> {
     pub fn split_suffix(self) -> anyhow::Result<(Self, Self)> {
         self.ensure_fit()?;
         let point = self.bytes().len() - Self::target_size();
-        let (head, tail) = self.buf.split_at(point);
+        let (head, tail) = self
+            .buf
+            .split_at(point)
+            .map_err(|_| anyhow::anyhow!("Failed to split buffer!"))?;
         Ok((Self::new(head), Self::new(tail)))
     }
 
@@ -282,7 +297,10 @@ impl<B: ByteSlice, T> RefMaker<B, T> {
     }
 }
 
-impl<B: ByteSliceMut, T> RefMaker<B, T> {
+impl<B: SplitByteSliceMut, T> RefMaker<B, T>
+where
+    T: KnownLayout + Immutable,
+{
     /// Creates a zeroized reference of type `T` from the buffer.
     ///
     /// # Errors
@@ -312,7 +330,10 @@ impl<B: ByteSliceMut, T> RefMaker<B, T> {
     }
 }
 
-impl<B: ByteSliceMut, T> Zeroize for RefMaker<B, T> {
+impl<B: SplitByteSliceMut, T> Zeroize for RefMaker<B, T>
+where
+    T: KnownLayout + Immutable,
+{
     fn zeroize(&mut self) {
         self.bytes_mut().zeroize()
     }
diff --git a/util/src/zerocopy/zerocopy_ref_ext.rs b/util/src/zerocopy/zerocopy_ref_ext.rs
index fa3c1b3..9d883b5 100644
--- a/util/src/zerocopy/zerocopy_ref_ext.rs
+++ b/util/src/zerocopy/zerocopy_ref_ext.rs
@@ -1,7 +1,7 @@
 //! Extension traits for converting `Ref<B, T>` into references backed by
 //! standard slices.
 
-use zerocopy::{ByteSlice, ByteSliceMut, Ref};
+use zerocopy::{SplitByteSlice, SplitByteSliceMut, Immutable, KnownLayout, Ref};
 
 /// A trait for converting a `Ref<B, T>` into a `Ref<&[u8], T>`.
 ///
@@ -16,7 +16,7 @@ pub trait ZerocopyEmancipateExt<B, T> {
     ///
     /// ```
     /// # use std::ops::Deref;
-    /// # use zerocopy::{AsBytes, ByteSlice, FromBytes, FromZeroes, Ref};
+    /// # use zerocopy::{AsBytes, SplitByteSlice, FromBytes, FromZeroes, Ref};
     /// # use rosenpass_util::zerocopy::ZerocopyEmancipateExt;
     /// #[derive(FromBytes, FromZeroes, AsBytes)]
     /// #[repr(C)]
@@ -64,18 +64,20 @@ pub trait ZerocopyEmancipateMutExt<B, T> {
 
 impl<B, T> ZerocopyEmancipateExt<B, T> for Ref<B, T>
 where
-    B: ByteSlice,
+    B: SplitByteSlice,
+    T: KnownLayout + Immutable,
 {
     fn emancipate(&self) -> Ref<&[u8], T> {
-        Ref::new(self.bytes()).unwrap()
+        Ref::new(zerocopy::Ref::<B, T>::bytes(&self)).unwrap()
     }
 }
 
 impl<B, T> ZerocopyEmancipateMutExt<B, T> for Ref<B, T>
 where
-    B: ByteSliceMut,
+    B: SplitByteSliceMut,
+    T: KnownLayout + Immutable,
 {
     fn emancipate_mut(&mut self) -> Ref<&mut [u8], T> {
-        Ref::new(self.bytes_mut()).unwrap()
+        Ref::new(zerocopy::Ref::<B, T>::bytes_mut(self)).unwrap()
     }
 }
diff --git a/util/src/zerocopy/zerocopy_slice_ext.rs b/util/src/zerocopy/zerocopy_slice_ext.rs
index 3dd5393..27a4214 100644
--- a/util/src/zerocopy/zerocopy_slice_ext.rs
+++ b/util/src/zerocopy/zerocopy_slice_ext.rs
@@ -1,7 +1,7 @@
 //! Extension traits for parsing slices into [`zerocopy::Ref`] values using the
 //! [`RefMaker`] abstraction.
 
-use zerocopy::{ByteSlice, ByteSliceMut, Ref};
+use zerocopy::{Immutable, KnownLayout, Ref, SplitByteSlice, SplitByteSliceMut};
 
 use super::RefMaker;
 
@@ -9,7 +9,7 @@ use super::RefMaker;
 ///
 /// This trait adds methods for creating [`Ref`] references from
 /// slices by using the [`RefMaker`] type internally.
-pub trait ZerocopySliceExt: Sized + ByteSlice {
+pub trait ZerocopySliceExt: Sized + SplitByteSlice {
     /// Creates a new `RefMaker` for the given slice.
     ///
     /// # Example
@@ -52,7 +52,10 @@ pub trait ZerocopySliceExt: Sized + ByteSlice {
     /// assert_eq!(data_ref.0, 0x0201);
     /// assert_eq!(data_ref.1, 0x0403);
     /// ```
-    fn zk_parse<T>(self) -> anyhow::Result<Ref<Self, T>> {
+    fn zk_parse<T>(self) -> anyhow::Result<Ref<Self, T>>
+    where
+        T: Immutable + KnownLayout,
+    {
         self.zk_ref_maker().parse()
     }
 
@@ -80,7 +83,10 @@ pub trait ZerocopySliceExt: Sized + ByteSlice {
     /// let header_ref = bytes.0.zk_parse_prefix::<Header>().unwrap();
     /// assert_eq!(header_ref.0, 0xDDCCBBAA);
     /// ```
-    fn zk_parse_prefix<T>(self) -> anyhow::Result<Ref<Self, T>> {
+    fn zk_parse_prefix<T>(self) -> anyhow::Result<Ref<Self, T>>
+    where
+        T: Immutable + KnownLayout,
+    {
         self.zk_ref_maker().from_prefix()?.parse()
     }
 
@@ -108,18 +114,21 @@ pub trait ZerocopySliceExt: Sized + ByteSlice {
     /// let header_ref = bytes.0.zk_parse_suffix::<Header>().unwrap();
     /// assert_eq!(header_ref.0, 0x30201000);
     /// ```
-    fn zk_parse_suffix<T>(self) -> anyhow::Result<Ref<Self, T>> {
+    fn zk_parse_suffix<T>(self) -> anyhow::Result<Ref<Self, T>>
+    where
+        T: Immutable + KnownLayout,
+    {
         self.zk_ref_maker().from_suffix()?.parse()
     }
 }
 
-impl<B: ByteSlice> ZerocopySliceExt for B {}
+impl<B: SplitByteSlice> ZerocopySliceExt for B {}
 
 /// Extension trait for zero-copy parsing of mutable slices with zeroization
 /// capabilities.
 ///
 /// Provides convenience methods to create zero-initialized references.
-pub trait ZerocopyMutSliceExt: ZerocopySliceExt + Sized + ByteSliceMut {
+pub trait ZerocopyMutSliceExt: ZerocopySliceExt + Sized + SplitByteSliceMut {
     /// Creates a new zeroized reference from the entire slice.
     ///
     /// This zeroizes the slice first, then provides a `Ref`.
@@ -143,7 +152,10 @@ pub trait ZerocopyMutSliceExt: ZerocopySliceExt + Sized + ByteSliceMut {
     /// assert_eq!(data_ref.0, [0,0,0,0]);
     /// assert_eq!(bytes.0, [0, 0, 0, 0]);
     /// ```
-    fn zk_zeroized<T>(self) -> anyhow::Result<Ref<Self, T>> {
+    fn zk_zeroized<T>(self) -> anyhow::Result<Ref<Self, T>>
+    where
+        T: Immutable + KnownLayout,
+    {
         self.zk_ref_maker().make_zeroized()
     }
 
@@ -171,7 +183,10 @@ pub trait ZerocopyMutSliceExt: ZerocopySliceExt + Sized + ByteSliceMut {
     /// assert_eq!(data_ref.0, [0,0,0,0]);
     /// assert_eq!(bytes.0, [0, 0, 0, 0, 0xFF, 0xFF]);
     /// ```
-    fn zk_zeroized_from_prefix<T>(self) -> anyhow::Result<Ref<Self, T>> {
+    fn zk_zeroized_from_prefix<T>(self) -> anyhow::Result<Ref<Self, T>>
+    where
+        T: Immutable + KnownLayout,
+    {
         self.zk_ref_maker().from_prefix()?.make_zeroized()
     }
 
@@ -199,9 +214,12 @@ pub trait ZerocopyMutSliceExt: ZerocopySliceExt + Sized + ByteSliceMut {
     /// assert_eq!(data_ref.0, [0,0,0,0]);
     /// assert_eq!(bytes.0, [0xFF, 0xFF, 0, 0, 0, 0]);
     /// ```
-    fn zk_zeroized_from_suffix<T>(self) -> anyhow::Result<Ref<Self, T>> {
+    fn zk_zeroized_from_suffix<T>(self) -> anyhow::Result<Ref<Self, T>>
+    where
+        T: Immutable + KnownLayout,
+    {
         self.zk_ref_maker().from_suffix()?.make_zeroized()
     }
 }
 
-impl<B: ByteSliceMut> ZerocopyMutSliceExt for B {}
+impl<B: SplitByteSliceMut> ZerocopyMutSliceExt for B {}
diff --git a/wireguard-broker/Cargo.toml b/wireguard-broker/Cargo.toml
index e43585c..c932cd6 100644
--- a/wireguard-broker/Cargo.toml
+++ b/wireguard-broker/Cargo.toml
@@ -41,6 +41,7 @@ rand = { workspace = true }
 procspawn = { workspace = true }
 
 [features]
+default = ["experiment_api"]
 experiment_api = ["rustix", "libc"]
 experiment_memfd_secret = []
 
diff --git a/wireguard-broker/src/api/client.rs b/wireguard-broker/src/api/client.rs
index 6e43953..a8d68d0 100644
--- a/wireguard-broker/src/api/client.rs
+++ b/wireguard-broker/src/api/client.rs
@@ -38,6 +38,8 @@
 
 use std::{borrow::BorrowMut, fmt::Debug};
 
+use zerocopy::IntoBytes;
+
 use crate::{
     api::{
         config::NetworkBrokerConfig,
@@ -219,7 +221,7 @@ where
         // Send message
         self.io
             .borrow_mut()
-            .send_msg(req.bytes())
+            .send_msg(req.as_bytes())
             .map_err(IoError)?;
 
         Ok(())
diff --git a/wireguard-broker/src/api/msgs.rs b/wireguard-broker/src/api/msgs.rs
index 4ed1fa3..d64933a 100644
--- a/wireguard-broker/src/api/msgs.rs
+++ b/wireguard-broker/src/api/msgs.rs
@@ -3,7 +3,7 @@
 
 use std::str::{from_utf8, Utf8Error};
 
-use zerocopy::{AsBytes, FromBytes, FromZeroes};
+use zerocopy::{FromBytes, Immutable, IntoBytes, KnownLayout};
 
 /// The number of bytes reserved for overhead when packaging data.
 pub const ENVELOPE_OVERHEAD: usize = 1 + 3;
@@ -15,8 +15,8 @@ pub const RESPONSE_MSG_BUFFER_SIZE: usize = ENVELOPE_OVERHEAD + 1;
 
 /// Envelope for messages being passed around.
 #[repr(packed)]
-#[derive(AsBytes, FromBytes, FromZeroes)]
-pub struct Envelope<M: AsBytes + FromBytes> {
+#[derive(IntoBytes, FromBytes, Immutable, KnownLayout)]
+pub struct Envelope<M: IntoBytes + FromBytes> {
     /// [MsgType] of this message
     pub msg_type: u8,
     /// Reserved for future use
@@ -29,7 +29,7 @@ pub struct Envelope<M: AsBytes + FromBytes> {
 /// # Example
 ///
 #[repr(packed)]
-#[derive(AsBytes, FromBytes, FromZeroes)]
+#[derive(IntoBytes, FromBytes, Immutable, KnownLayout)]
 pub struct SetPskRequest {
     /// The pre-shared key.
     pub psk: [u8; 32],
@@ -85,7 +85,7 @@ impl SetPskRequest {
 
 /// Message format for response to the set pre-shared key operation.
 #[repr(packed)]
-#[derive(AsBytes, FromBytes, FromZeroes)]
+#[derive(IntoBytes, FromBytes, Immutable, KnownLayout)]
 pub struct SetPskResponse {
     pub return_code: u8,
 }
diff --git a/wireguard-broker/src/api/server.rs b/wireguard-broker/src/api/server.rs
index 9a55b3d..2f0ca0b 100644
--- a/wireguard-broker/src/api/server.rs
+++ b/wireguard-broker/src/api/server.rs
@@ -8,6 +8,7 @@
 use std::borrow::BorrowMut;
 
 use rosenpass_secret_memory::{Public, Secret};
+use zerocopy::IntoBytes;
 
 use crate::api::msgs::{self, Envelope, SetPskRequest, SetPskResponse};
 use crate::WireGuardBroker;
@@ -85,7 +86,7 @@ where
         res.msg_type = msgs::MsgType::SetPsk as u8;
         self.handle_set_psk(&req.payload, &mut res.payload)?;
 
-        Ok(res.bytes().len())
+        Ok(res.as_bytes().len())
     }
 
     /// Sets the pre-shared key for the interface identified in `req` to the pre-shared key