Multicast Key Management Scheme Based on TOFT

Key management is very crucial in a secure multicast system. The key storage of the group controller and group members, the communication cost and computation cost caused by joining/leaving members, are the determining factors for the performance of the key management system. A scheme is high-performed, if it has the optimal rekeying cost and the lower storage requirements. In order to get the high efficiency and security, a novel scheme (TOFT) based on threshold-based one-way function tree is proposed in this paper. The quad-tree and the threshold-key-mechanism are used in the scheme, which improves the performance of the key management system. We present the design principle, the realization protocols including keys generation and distribution, dynamic membership management. The TOFT scheme is compared with other protocols from the following four aspects: computation cost, communication cost, storage requirements, and security. Finally, we conclude that our scheme is more efficient than others.