摘要 |
In a communication system (100), a method provides for message integrity regardless of the operating version of an authentication center (198) or an interface (197) between the authentication center (198) and a mobile switching center (199). The method includes generating a cellular message encryption algorithm (CMEA) key, and generating a CMEA-key-derived integrity key (CIK) based on the CMEA key for message integrity between a mobile station and a base station. The mobile station transmits a registration message to the base station, and determines an operating version of the authentication center (198) in communication with the base station based on whether the mobile station receives a registration accepted order or some elements of an authentication vector from the base station. The CIK is generated based on the CMEA key, if the mobile station receives a valid registration accepted order from the base station. |