diff --git a/src/CAServer.Application.Contracts/Commons/SignatureKeyHelp.cs b/src/CAServer.Application.Contracts/Commons/SignatureKeyHelp.cs
index cd1bbfe43..98db1ef38 100644
--- a/src/CAServer.Application.Contracts/Commons/SignatureKeyHelp.cs
+++ b/src/CAServer.Application.Contracts/Commons/SignatureKeyHelp.cs
@@ -1,9 +1,9 @@
-using System;
-using System.Security.Cryptography;
+using AElf;
+using AElf.Cryptography;
 
 namespace CAServer.Commons;
 
 public static class SignatureKeyHelp
 {
-    public static string  CommonPrivateKeyForCallTx { get; set; } = Convert.ToBase64String(ECDsa.Create().ExportPkcs8PrivateKey());
+    public static string CommonPrivateKeyForCallTx { get; set; } = CryptoHelper.GenerateKeyPair().PrivateKey.ToHex();
 }
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