An Efficient Rekeying Approach for Secure Multicast Communication

To provide communication confidentiality in multicasting applications, traffic data in secure multicast is encrypted with a session key known only by certificated group members. Whenever there is a change in the group membership, the session key must be updated dynamically. Previous work has been focused on individual rekeying, there are two problems with individual rekeying: inefficiency and an out of sync problem between keys and data. This paper devises a batch rekeying scheme based on iterated hash function which can improve efficiency of the key server,and analyzes the key server's processing cost for batch rekeying.The simulation results show that our batch scheme,which is based on iterated hash function, compared to individual rekeying, saves server cost efficiently.