diff --git a/common/crypto/src/identity/mod.rs b/common/crypto/src/identity/mod.rs
new file mode 100644
index 0000000000..175806394e
--- /dev/null
+++ b/common/crypto/src/identity/mod.rs
@@ -0,0 +1,38 @@
+
+pub trait MixnetIdentityKeyPair<Priv, Pub>
+where
+    Priv: MixnetIdentityPrivateKey,
+    Pub: MixnetIdentityPublicKey,
+{
+    fn new() -> Self;
+    fn private_key(&self) -> &Priv;
+    fn public_key(&self) -> &Pub;
+
+    // TODO: signing related methods
+}
+
+pub trait MixnetIdentityPublicKey:
+    Sized + for<'a> From<&'a <Self as MixnetIdentityPublicKey>::PrivateKeyMaterial>
+{
+    // we need to couple public and private keys together
+    type PrivateKeyMaterial: MixnetIdentityPrivateKey<PublicKeyMaterial = Self>;
+
+    fn to_bytes(&self) -> Vec<u8>;
+    fn from_bytes(b: &[u8]) -> Self;
+}
+
+pub trait MixnetIdentityPrivateKey: Sized {
+    // we need to couple public and private keys together
+    type PublicKeyMaterial: MixnetIdentityPublicKey<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;
+}
+
+// same for validator
+