After a decade of exponential growth, wireless technologies have profoundly impacted people’s lifestyles. Wireless networks provide users with greater flexibility and benefit by anytime and anywhere services (Pahlavan & Krishnamurthy, 2002). At the same time, rapid developments in multicast have led to the emergence of many multicast applications, such as stock quoting, multimedia conferencing and network gaming. Therefore it is reasonable to believe that the integration of wireless and multicast will benefit mobile users. Before the customers can enjoy the efficiency and convenience of wireless multicasts, access control must be employed to guarantee that only legitimate users can utilize the multicast services.