Patent ID: 8126144

Claim:
An apparatus comprising: a storage medium to store an authentication key context including an uplink packet number and a downlink packet number that respectively correspond to a media access control (MAC) message received by the apparatus from a mobile subscriber station and a downlink MAC message transmitted to the mobile subscriber station from the apparatus, the authentication key context corresponding to an authentication key associated with authenticating the mobile subscriber station to be serviced in a coverage area of an access network serviced by the apparatus, the mobile subscriber station to be serviced while the authentication key remains unexpired; and an authentication module coupled to the storage medium and configured to purge the authentication key and the authentication key context of the mobile subscriber station from the storage medium when the apparatus hands off the mobile subscriber station to be serviced in another coverage area of the access network by another apparatus and prior to expiration of the authentication key of the mobile subscriber station, receive, subsequent to the authentication key and the authentication key context being purged, a range request MAC message from the mobile subscriber station, the range request MAC message including the authentication key context, and retrieve, from an authenticator of the access network, the authentication key based at least in part on the received range request MAC message.