A Novel Key Assignment Algorithms for Secure Multicast

Group key management has been one of important problems all the time for secure multicast. Key assignment algorithm plays a very important role in the large and dynamic groups for group key management. This paper investigates detailed and deeply key assignment algorithms and analyses breadth first assignment (BFA) and depth first assignment(DFA). Combining the advantage and disadvantage of these two kinds of algorithms, we present a new mixed key assignment algorithm (MKA). Our results show that this approach is much better than previous key assignment algorithms for reducing the average number of packets that a user needs to receive and the variance of it. For stage of rekey retransmission, we use a method that assigns the keys of different members into one packet. The approach can be very effective in reducing the bandwidth requirements of the reliable key delivery.