diff --git a/src/libs/crypto/index.ts b/src/libs/crypto/index.ts
index 8d8df5a..a71cec1 100644
--- a/src/libs/crypto/index.ts
+++ b/src/libs/crypto/index.ts
@@ -122,7 +122,7 @@ export const accessToken = async (identifier: IIdentifier) => {
     : privateKeyHex;
   const privateKeyBytes = u8a.fromString(input.toLowerCase(), "base16");
 
-  const signer = didJwt.ES256KSigner(privateKeyBytes, true);
+  const signer = didJwt.SimpleSigner(privateKeyHex);
 
   const nowEpoch = Math.floor(Date.now() / 1000);
   const endEpoch = nowEpoch + 60; // add one minute
@@ -143,7 +143,7 @@ export const sign = async (privateKeyHex: string) => {
     : privateKeyHex;
   const privateKeyBytes = u8a.fromString(input.toLowerCase(), "base16");
 
-  const signer = didJwt.ES256KSigner(privateKeyBytes, true);
+  const signer = didJwt.SimpleSigner(privateKeyHex);
 
   return signer;
 };