Subset Difference Revocation (SDR) [7] has been proposed to perform group rekeying in a stateless manner. However, statelessness comes at a cost in terms of key storage and messaging overhead when the number of currently active members is much smaller than the number of potential group members [3]. In this paper, we propose a dynamic SDR scheme to address these two problems. Briefly, rather tha...

MUGI [15] is a word-based stream cipher designed for 64bit architectures. It uses a 128-bit master key and a 128-bit initialization vector to populate a large non-linear feedback shift register (NLFSR) and additional non-linear state (NLS). In standard benchmarks on 32-bit processors, MUGI suffers from poor key agility because it is implemented on an architecture for which it is not designed, a...

In secure group communications, a key server can deliver a “group-oriented” rekey message [16] to a large number of users efficiently using IP multicast. For reliable delivery, Keystone [17] proposed the use of forward error correction (FEC) in an initial multicast, followed by the use of unicast delivery for users that cannot recover their new keys from the multicast. In this paper, we investi...

Scalability is one of the most important requirements for secure multicast in a multi-group environment. In this study, we propose a decentralized multi-group key management scheme that allows each multicast group sender to control the access to its group communication independently. Scalability is enhanced by local rekeying and inter-working among different subgroups. The group key secrecy and...