Dynamic rekeying in 3GPP multimedia broadcast/multicast service (MBMS)

In multicast, it is important to update security keys when a user joins or leaves the multicast group. In this paper, we study how to reduce the cost to update the security keys in 3GPP MBMS. The problem is especially critical for MBMS because 3G is a large scale network with huge number of mobile users. We show that with dynamic rekeying, the cost can be reduced significantly.