Host mobility key management in dynamic secure group communication

The key management has a fundamental role in securing group communications taking place over vast and unprotected networks. It is concerned with the distribution and update of the keying materials whenever any changes occur in the group membership. Wireless mobile environments enable members to move freely within the networks, which causes more difficulty to design efficient and scalable key management protocols. This is partly because both member location dynamic and group membership dynamic must be managed concurrently, which may lead to significant rekeying overhead. This paper presents a hierarchical group key management scheme taking the mobility of members into consideration intended for wireless mobile environments. The proposed scheme supports the mobility of members across wireless mobile environments while remaining in the group session with minimum rekeying transmission overhead. Furthermore, the proposed scheme alleviates 1-affect-n phenomenon, single point of failure, and signaling load caused by moving members at the core network. Simulation results shows that the scheme surpasses other existing efforts in terms of communication overhead and affected members. The security requirements studies also show the backward and forward secrecy is preserved in the proposed scheme even though the members move between areas

Scalable balanced batch rekeying for secure group communication

Secure group communication is important for applications such as pay-per-view. Other authors have proposed the key tree approach to distribute a shared group key in a way such that the rekeying cost scales linearly with the logarithm of the group size for a join or depart request. The efficiency of the key tree approach depends critically on whether the key tree remains balanced. Periodic rebalancing can be used to balance the key tree whenever it becomes unbalanced but this adds extra costs to the network. In this paper, we present two Merging Algorithms suitable for batch join events. As the multicast session consists of other events as well, we then show how we can extend our algorithms into existing work to minimise the maximum difference in height without adding extra network costs. Simulation results show our Merging Algorithms not only balance the key tree but their rekeying costs are lower compared to existing algorithms. (C) 2006 Elsevier Ltd. All rights reserved

Scalable balanced batch rekeying for secure group communication

Secure group communication is important for applications such as pay-per-view. Other authors have proposed the key tree approach to distribute a shared group key in a way such that the rekeying cost scales linearly with the logarithm of the group size for a join or depart request. The efficiency of the key tree approach depends critically on whether the key tree remains balanced. Periodic rebalancing can be used to balance the key tree whenever it becomes unbalanced but this adds extra costs to the network. In this paper, we present two Merging Algorithms suitable for batch join events. As the multicast session consists of other events as well, we then show how we can extend our algorithms into existing work to minimise the maximum difference in height without adding extra network costs. Simulation results show our Merging Algorithms not only balance the key tree but their rekeying costs are lower compared to existing algorithms. (C) 2006 Elsevier Ltd. All rights reserved