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.