diff --git a/src/main/java/com/danubetech/didcomm/JwtObject.java b/src/main/java/com/danubetech/didcomm/JwtObject.java
index 0b5920c..5bd39fe 100644
--- a/src/main/java/com/danubetech/didcomm/JwtObject.java
+++ b/src/main/java/com/danubetech/didcomm/JwtObject.java
@@ -12,6 +12,7 @@
 import org.erdtman.jcs.JsonCanonicalizer;
 
 import java.io.IOException;
+import java.security.KeyPair;
 import java.security.interfaces.RSAPrivateKey;
 import java.security.interfaces.RSAPublicKey;
 import java.util.Map;
@@ -61,11 +62,11 @@ public String sign_RSA_PS256(ByteSigner signer) throws JOSEException {
 		return this.sign_RSA_PS256(signer, null, false);
 	}
 
-	public String sign_RSA_PS256(RSAPrivateKey privateKey, String kid, boolean canonicalize) throws JOSEException {
+	public String sign_RSA_PS256(KeyPair privateKey, String kid, boolean canonicalize) throws JOSEException {
 		return this.sign_RSA_PS256(new RSA_PS256_PrivateKeySigner(privateKey), kid, canonicalize);
 	}
 
-	public String sign_RSA_PS256(RSAPrivateKey privateKey) throws JOSEException {
+	public String sign_RSA_PS256(KeyPair   privateKey) throws JOSEException {
 		return this.sign_RSA_PS256(privateKey, null, false);
 	}
 
@@ -85,11 +86,11 @@ public String sign_RSA_RS256(ByteSigner signer) throws JOSEException {
 		return this.sign_RSA_RS256(signer, null, false);
 	}
 
-	public String sign_RSA_RS256(RSAPrivateKey privateKey, String kid, boolean canonicalize) throws JOSEException {
+	public String sign_RSA_RS256(KeyPair privateKey, String kid, boolean canonicalize) throws JOSEException {
 		return this.sign_RSA_RS256(new RSA_RS256_PrivateKeySigner(privateKey), kid, canonicalize);
 	}
 
-	public String sign_RSA_RS256(RSAPrivateKey privateKey) throws JOSEException {
+	public String sign_RSA_RS256(KeyPair privateKey) throws JOSEException {
 		return this.sign_RSA_RS256(privateKey, null, false);
 	}