A comparative performance analysis of reliable group rekey transport protocols for secure multicast

In this paper, we present a new scalable and reliable key distribution protocol for group key management schemes that use logical key hierarchies (LKH) for scalable group rekeying. Our protocol called WKA-BKR is based upon two ideas—weighted key assignment and batched key retransmission—both of which exploit the special properties of LKH and the group rekey transport payload to reduce the bandwidth overhead of the reliable key delivery protocol. Using both analytic modeling and simulation, we compare the performance of WKA-BKR with that of other rekey transport protocols, including a recently proposed protocol based on proactive FEC. Our results show that for most network loss scenarios, the bandwidth used by WKA-BKR is lower than that of the other protocols.