Adding Reliable and Self-healing Key Distribution to the Subset Difference Group Rekeying Method for Secure Multicast

摘要

We study two important issues related to the Subset Difference Rekeying (SDR) method [4]. First, we present a reliable key distribution scheme, called WFEC-BKR, that enables members to receive the current group key in a reliable and timely fashion inspite of packet losses in the network. Through simulation ,we show that in most scenarios, WFEC-BKR outperforms previously proposed schemes for reliable rekey transport, Second, we present a group key recovery scheme that adds the self-healing property to SDR, i.e., our scheme enables a member that has missed up to a certain number m of previous rekey operations to recover the missing group keys without asking th key server for retransmission. The additional communication overhead imposed by our key recovery scheme is quite small (less than 3m additional keys).