An efficient batch rekeying scheme based on one-way function tree

Existing methods for handling group key updating in a multicast environment are mainly based on centralized hierarchical key tree, but they can´t meet the demands for highly dynamic applications with large group size of up to 2¹⁸ or more, as their scalabilities are limited by time cost and available multicast bandwidth. An efficient batch rekeying scheme based on one-way function tree (OFT) and minimum exact covering is presented in this paper. Result shows that our algorithm is more efficient than previous schemes and can achieve desired scalability in terms of computational and communication overhead.