diff --git a/pbc_client/__init__.py b/pbc_client/__init__.py
index 4833b42..9b3fc94 100644
--- a/pbc_client/__init__.py
+++ b/pbc_client/__init__.py
@@ -67,18 +67,16 @@ class SenderAuthentication:
     secret_key: str
 
     def sender_address(self) -> Address:
-        derp = self._signing_key().verifying_key.to_string()
-        hashed = HashSha256.of_bytes(derp)
-        print(derp.hex())
-        print(derp)
-        print(hashed)
+        verifying_key_repr = self._signing_key().get_verifying_key().to_string("uncompressed")
+        hashed = HashSha256.of_bytes(verifying_key_repr)
         return Address(b'\0' + hashed._bytes[-20:])
 
     def sign_hash(self, _hash: HashSha256) -> Signature:
         return Signature(self._signing_key().sign(_hash._bytes))
 
     def _signing_key(self):
-        return ecdsa.SigningKey.from_string(bytearray.fromhex(self.secret_key), curve=ecdsa.SECP256k1)
+        secret_exponent = int(self.secret_key, 16)
+        return ecdsa.SigningKey.from_secret_exponent(secret_exponent , curve=ecdsa.SECP256k1)
 
 TRANSACTION_VALIDITY_DURATION = 60