Fast rekeying of multidimensional hierarchical tree in multi-object multimedia multicast

Multi-object multimedia multicast services consist of users that subscribe to different secure levels or different sets of data streams. These services need a security mechanism to ensure hierarchical access control. Existing methods based on traditional schemes are not efficient for multi-object multicasts. In this paper, we present a multi-dimensional hierarchical tree scheme that maintains all members with different access privileges in an integrated way, and propose a fast rekeying algorithm based on minimum exact covering theory. Compared with recent works, the proposed scheme can greatly improve the efficiency of group updating in terms of time cost, bandwidth.