LOCAL AUTHENTICATION IN A COMMUNICATION SYSTEM

摘要

Methods and apparatus are presented for providing local authentication of subscribers travelling outside their home systems. A subscriber identification token (230) provides authentication support by generating a signature (370) based upon a key that is held secret from a mobile unit (220). A mobile unit (220) that is programmed to wrongfully retain keys from a subscriber identification token (230) after a subscriber has removed his or her token is prevented from subsequently accessing the subscriber's account.