diff --git a/acme_common/src/crypto.rs b/acme_common/src/crypto.rs
index 7ef5338..0cd50d6 100644
--- a/acme_common/src/crypto.rs
+++ b/acme_common/src/crypto.rs
@@ -6,6 +6,7 @@ mod openssl_hash;
 mod standalone_hash;
 
 mod openssl_keys;
+mod key_type;
 
 #[cfg(not(feature = "standalone"))]
 pub const DEFAULT_ALGO: &str = "rsa2048";
@@ -19,4 +20,5 @@ pub use openssl_hash::sha256;
 #[cfg(feature = "standalone")]
 pub use standalone_hash::sha256;
 
-pub use openssl_keys::{gen_keypair, KeyPair, KeyType};
+pub use openssl_keys::{gen_keypair, KeyPair};
+pub use key_type::KeyType;
diff --git a/acme_common/src/crypto/key_type.rs b/acme_common/src/crypto/key_type.rs
new file mode 100644
index 0000000..34a6676
--- /dev/null
+++ b/acme_common/src/crypto/key_type.rs
@@ -0,0 +1,40 @@
+use crate::error::Error;
+use std::fmt;
+use std::str::FromStr;
+
+#[derive(Clone, Copy, Debug)]
+pub enum KeyType {
+    Curve25519,
+    EcdsaP256,
+    EcdsaP384,
+    Rsa2048,
+    Rsa4096,
+}
+
+impl FromStr for KeyType {
+    type Err = Error;
+
+    fn from_str(s: &str) -> Result<Self, Error> {
+        match s.to_lowercase().as_str() {
+            "ed25519" => Ok(KeyType::Curve25519),
+            "ecdsa_p256" => Ok(KeyType::EcdsaP256),
+            "ecdsa_p384" => Ok(KeyType::EcdsaP384),
+            "rsa2048" => Ok(KeyType::Rsa2048),
+            "rsa4096" => Ok(KeyType::Rsa4096),
+            _ => Err(format!("{}: unknown algorithm.", s).into()),
+        }
+    }
+}
+
+impl fmt::Display for KeyType {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let s = match self {
+            KeyType::Curve25519 => "ed25519",
+            KeyType::EcdsaP256 => "ecdsa-p256",
+            KeyType::EcdsaP384 => "ecdsa-p384",
+            KeyType::Rsa2048 => "rsa2048",
+            KeyType::Rsa4096 => "rsa4096",
+        };
+        write!(f, "{}", s)
+    }
+}
diff --git a/acme_common/src/crypto/openssl_keys.rs b/acme_common/src/crypto/openssl_keys.rs
index 770628b..f2979da 100644
--- a/acme_common/src/crypto/openssl_keys.rs
+++ b/acme_common/src/crypto/openssl_keys.rs
@@ -1,4 +1,5 @@
 use crate::b64_encode;
+use crate::crypto::KeyType;
 use crate::error::Error;
 use openssl::bn::{BigNum, BigNumContext};
 use openssl::ec::{EcGroup, EcKey};
@@ -7,8 +8,6 @@ use openssl::nid::Nid;
 use openssl::pkey::{Id, PKey, Private};
 use openssl::rsa::Rsa;
 use serde_json::json;
-use std::fmt;
-use std::str::FromStr;
 
 macro_rules! get_key_type {
     ($key: expr) => {
@@ -34,40 +33,6 @@ macro_rules! get_key_type {
     };
 }
 
-#[derive(Clone, Copy, Debug)]
-pub enum KeyType {
-    EcdsaP256,
-    EcdsaP384,
-    Rsa2048,
-    Rsa4096,
-}
-
-impl FromStr for KeyType {
-    type Err = Error;
-
-    fn from_str(s: &str) -> Result<Self, Error> {
-        match s.to_lowercase().as_str() {
-            "ecdsa_p256" => Ok(KeyType::EcdsaP256),
-            "ecdsa_p384" => Ok(KeyType::EcdsaP384),
-            "rsa2048" => Ok(KeyType::Rsa2048),
-            "rsa4096" => Ok(KeyType::Rsa4096),
-            _ => Err(format!("{}: unknown algorithm.", s).into()),
-        }
-    }
-}
-
-impl fmt::Display for KeyType {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        let s = match self {
-            KeyType::EcdsaP256 => "ecdsa-p256",
-            KeyType::EcdsaP384 => "ecdsa-p384",
-            KeyType::Rsa2048 => "rsa2048",
-            KeyType::Rsa4096 => "rsa4096",
-        };
-        write!(f, "{}", s)
-    }
-}
-
 pub struct KeyPair {
     pub key_type: KeyType,
     pub inner_key: PKey<Private>,
@@ -95,10 +60,9 @@ impl KeyPair {
 
     pub fn sign(&self, data: &[u8]) -> Result<Vec<u8>, Error> {
         match self.key_type {
-            KeyType::Rsa2048 | KeyType::Rsa4096 => {
-                // TODO: implement RSA signatures
-                Err("RSA signatures are not implemented yet".into())
-            }
+            KeyType::Curve25519 => {
+                Err("Curve25519 signatures are not implemented yet".into())
+            },
             KeyType::EcdsaP256 | KeyType::EcdsaP384 => {
                 let signature = EcdsaSig::sign(data, self.inner_key.ec_key()?.as_ref())?;
                 let r = signature.r().to_vec();
@@ -107,13 +71,20 @@ impl KeyPair {
                 signature.append(&mut s);
                 Ok(signature)
             }
+            KeyType::Rsa2048 | KeyType::Rsa4096 => {
+                // TODO: implement RSA signatures
+                Err("RSA signatures are not implemented yet".into())
+            }
         }
     }
 
     pub fn get_jwk_thumbprint(&self) -> Result<String, Error> {
+        // TODO: implement Curve25519 and RSA JWK thumbprint
         match self.key_type {
+            KeyType::Curve25519 => {
+                Err("Curve25519 thumbprint are not implemented yet".into())
+            },
             KeyType::EcdsaP256 | KeyType::EcdsaP384 => self.get_nist_ec_jwk(),
-            // TODO: implement RSA JWK thumbprint
             KeyType::Rsa2048 | KeyType::Rsa4096 => {
                 Err("RSA jwk thumbprint are not implemented yet".into())
             }
@@ -178,10 +149,11 @@ fn gen_ec_pair(nid: Nid) -> Result<PKey<Private>, Error> {
 
 pub fn gen_keypair(key_type: KeyType) -> Result<KeyPair, Error> {
     let priv_key = match key_type {
-        KeyType::Rsa2048 => gen_rsa_pair(2048),
-        KeyType::Rsa4096 => gen_rsa_pair(4096),
+        KeyType::Curve25519 => Err(Error::from("")),
         KeyType::EcdsaP256 => gen_ec_pair(Nid::X9_62_PRIME256V1),
         KeyType::EcdsaP384 => gen_ec_pair(Nid::SECP384R1),
+        KeyType::Rsa2048 => gen_rsa_pair(2048),
+        KeyType::Rsa4096 => gen_rsa_pair(4096),
     }
     .map_err(|_| Error::from(format!("Unable to generate a {} key pair.", key_type)))?;
     let key_pair = KeyPair {