AUTHENTICATION OF SUBSCRIBER STATION

摘要

The present invention relates to a telecommunication system comprising: at least one subscriber station (MS) in the memory (9, 9') of which a secret key (Ki) is stored, and authentication means (1, 3, 4, VLR) for authenticating said subscriber station. In order to make the subscriber-station-specific secret key even more difficult to crack, the subscriber station (MS) is arranged to check the correctness of a received input (RAND) by computing a message authentication code (MAC) by utilizing the input (RAND) and a checking algorithm (f), and to compute a response to be transmitted to the authentication means (VLR) by the subscriber station (MS) by utilizing an authentication algorithm (A3), said secret key (Ki) stored in the memory (9) of the subscriber station (MS) and the input (RAND) if the input (RAND) is correct on the basis of the message authentication code (MAC).