diff --git a/gen/rust/src/logoschat/encryption/logoschat.encryption.rs b/gen/rust/src/logoschat/encryption/logoschat.encryption.rs
index 9182844..dfb5773 100644
--- a/gen/rust/src/logoschat/encryption/logoschat.encryption.rs
+++ b/gen/rust/src/logoschat/encryption/logoschat.encryption.rs
@@ -1,7 +1,5 @@
 // @generated
 // This file is @generated by prost-build.
-/// TODO: This also encompasses plaintexts, is there a better name?
-/// Alternatives: ???
 #[derive(Clone, PartialEq, Eq, Hash, ::prost::Message)]
 pub struct EncryptedPayload {
     #[prost(oneof="encrypted_payload::Encryption", tags="1, 2, 3")]
@@ -16,7 +14,7 @@ pub mod encrypted_payload {
         #[prost(message, tag="2")]
         Doubleratchet(super::Doubleratchet),
         #[prost(message, tag="3")]
-        Xk0(super::Xk0),
+        InboxHandshake(super::InboxHandshakeV1),
     }
 }
 #[derive(Clone, PartialEq, Eq, Hash, ::prost::Message)]
@@ -39,17 +37,25 @@ pub struct Doubleratchet {
     pub aux: ::prost::alloc::string::String,
 }
 #[derive(Clone, PartialEq, Eq, Hash, ::prost::Message)]
-pub struct Xk0 {
-    #[prost(bytes="bytes", tag="1")]
-    pub initiator_static: ::prost::bytes::Bytes,
+pub struct InboxHandshakeV1 {
+    #[prost(message, optional, tag="1")]
+    pub header: ::core::option::Option<inbox_handshake_v1::InboxHeaderV1>,
     #[prost(bytes="bytes", tag="2")]
-    pub initiator_ephemeral: ::prost::bytes::Bytes,
-    #[prost(bytes="bytes", tag="3")]
-    pub responder_static: ::prost::bytes::Bytes,
-    /// Replace with RKI to save bytes
-    #[prost(bytes="bytes", tag="4")]
-    pub responder_ephemeral: ::prost::bytes::Bytes,
-    #[prost(bytes="bytes", tag="5")]
     pub payload: ::prost::bytes::Bytes,
 }
+/// Nested message and enum types in `InboxHandshakeV1`.
+pub mod inbox_handshake_v1 {
+    #[derive(Clone, PartialEq, Eq, Hash, ::prost::Message)]
+    pub struct InboxHeaderV1 {
+        #[prost(bytes="bytes", tag="1")]
+        pub initiator_static: ::prost::bytes::Bytes,
+        #[prost(bytes="bytes", tag="2")]
+        pub initiator_ephemeral: ::prost::bytes::Bytes,
+        #[prost(bytes="bytes", tag="3")]
+        pub responder_static: ::prost::bytes::Bytes,
+        /// Replace with RKI to save bytes
+        #[prost(bytes="bytes", tag="4")]
+        pub responder_ephemeral: ::prost::bytes::Bytes,
+    }
+}
 // @@protoc_insertion_point(module)
diff --git a/protos/encryption.proto b/protos/encryption.proto
index 58b7b43..1155bda 100644
--- a/protos/encryption.proto
+++ b/protos/encryption.proto
@@ -3,14 +3,12 @@ syntax = "proto3";
 package logoschat.encryption;
 
 
-// TODO: This also encompasses plaintexts, is there a better name?
-// Alternatives: ???
 message EncryptedPayload {
 
     oneof encryption {
         encryption.Plaintext plaintext = 1;
 		encryption.Doubleratchet doubleratchet = 2;
-        encryption.XK0 xk0 = 3;
+        encryption.InboxHandshakeV1 inbox_handshake = 3;
     }
 }
 
@@ -26,10 +24,14 @@ message Doubleratchet {
     string aux = 5;
 }
 
-message XK0 {
-    bytes initiator_static = 1;    
-    bytes initiator_ephemeral = 2;  
-    bytes responder_static = 3;    
-    bytes responder_ephemeral = 4; // Replace with RKI to save bytes
-    bytes payload = 5;
+message InboxHandshakeV1 {
+
+    message InboxHeaderV1 {
+        bytes initiator_static = 1;    
+        bytes initiator_ephemeral = 2;  
+        bytes responder_static = 3;    
+        bytes responder_ephemeral = 4; // Replace with RKI to save bytes
+    }
+    InboxHeaderV1 header = 1;
+    bytes payload = 2;
 }