Multi-layer key management for secure multimedia multicast communications

An important application of multicasting is group-oriented multimedia communication, such as video-on-demand and video conferencing. Before these services can be successfully deployed, security infrastructures must be developed to ensure access control to multicast content. In this paper, we present a multi-group key management scheme tailored to multimedia multicast services that distribute data in multi-layer or multi-object format. Compared with the existing tree-based key management schemes that are used for generic data multicasting services, the proposed scheme can reduce the communication overhead by a factor of M+1/2 and M is the number of layers. For example, when the multimedia data is encoded into three layers according to different quality requirements, the proposed scheme reduces the communication overhead associated with key updating by 50%.