diff --git a/common/crypto/src/encryption/mod.rs b/common/crypto/src/encryption/mod.rs
new file mode 100644
index 0000000000..a2db2b5dcd
--- /dev/null
+++ b/common/crypto/src/encryption/mod.rs
@@ -0,0 +1,36 @@
+pub mod x25519;
+
+pub trait MixnetEncryptionKeyPair<Priv, Pub>
+where
+    Priv: MixnetEncryptionPrivateKey,
+    Pub: MixnetEncryptionPublicKey,
+{
+    fn new() -> Self;
+    fn private_key(&self) -> &Priv;
+    fn public_key(&self) -> &Pub;
+
+    // TODO: encryption related methods
+}
+
+pub trait MixnetEncryptionPublicKey:
+    Sized + for<'a> From<&'a <Self as MixnetEncryptionPublicKey>::PrivateKeyMaterial>
+{
+    // we need to couple public and private keys together
+    type PrivateKeyMaterial: MixnetEncryptionPrivateKey<PublicKeyMaterial = Self>;
+
+    fn to_bytes(&self) -> Vec<u8>;
+    fn from_bytes(b: &[u8]) -> Self;
+}
+
+pub trait MixnetEncryptionPrivateKey: Sized {
+    // we need to couple public and private keys together
+    type PublicKeyMaterial: MixnetEncryptionPublicKey<PrivateKeyMaterial = Self>;
+
+    /// Returns the associated public key
+    fn public_key(&self) -> Self::PublicKeyMaterial {
+        self.into()
+    }
+
+    fn to_bytes(&self) -> Vec<u8>;
+    fn from_bytes(b: &[u8]) -> Self;
+}