Patent ID: 7873163
Filing Date: 2011-01-18
Classification: H04L,H04W

Abstract:
1. A method in a mobile station comprising: transmitting a registration message to a base station, wherein the registration message is based on a 2G authentication procedure; starting a key setup timer; generating a cellular message encryption algorithm (CMEA) key for use in registration based on the 2G authentication procedure; restarting the method using a new registration message if the key setup timer expires; receiving a registration response from the base station; determining an operating version of an authentication center in communication with said base station based on the registration response; and when the operating version is determined to be based on a 3G authentication procedure, stopping the key setup timer and using an integrity key (IK), based on an element of an authentication vector received in the registration response, for message integrity between said mobile station and said base station.