diff --git a/backend/mpc-system/services/server-party-api/cmd/server/main.go b/backend/mpc-system/services/server-party-api/cmd/server/main.go
index 2d207d84..7f4472fd 100644
--- a/backend/mpc-system/services/server-party-api/cmd/server/main.go
+++ b/backend/mpc-system/services/server-party-api/cmd/server/main.go
@@ -598,7 +598,7 @@ func runSigningProtocol(
 	// Create signing config
 	config := tss.SigningConfig{
 		Threshold:    t,
-		TotalParties: n,
+		TotalSigners: n,
 		Timeout:      5 * time.Minute,
 	}
 
@@ -632,7 +632,16 @@ func runSigningProtocol(
 		zap.String("session_id", sessionID.String()),
 		zap.String("party_id", partyID))
 
-	return result.Signature, result.R, result.S, result.V, nil
+	// Convert big.Int to []byte
+	var rBytes, sBytes []byte
+	if result.R != nil {
+		rBytes = result.R.Bytes()
+	}
+	if result.S != nil {
+		sBytes = result.S.Bytes()
+	}
+
+	return result.Signature, rBytes, sBytes, result.RecoveryID, nil
 }
 
 // messageHandler adapts MPCMessage channel to tss.MessageHandler