Key management for 3G MBMS security

The multimedia broadcast/multicast service (MBMS), which increases network efficiency, and facilitates group-oriented applications, is a service in 3G networks that is about to be standardized. A key security issue for MBMS is the design of a mechanism that controls access to multicast data. Traditionally, access control is done by distributing and maintaining key information. However, the existing architecture of mobile equipment prevents keys from being stored securely on the user side, making the traditional key management insufficient to protect the confidentiality of multicast data. Some discussion in 3GPP has addressed the issue, but the existing scheme achieves the security goal at the cost of high bandwidth overhead, unpredictable peak bandwidth and potential server implosion problems. Currently, no quantified convincing research has been done to study these issues. In this paper, we present new schemes that solve the problems, and quantify their scalability and bandwidth overhead.