A Novel Huffman Tree Scheme for Group Rekeying

For solving the problem that Huffman key tree can´t be adjusted dynamically but be statically established in current scheme, this paper proposes an adaptive Huffman key tree scheme for multicast rekeying. In the proposed scheme, the structure of Huffman key tree can be adjusted adaptively with the frequency of users joining in or leaving from multicast group before now, because that the frequency denotes the probability of this group member who would join in or leave from group in future. Our analysis proves that the scheme can provide the security of multicast rekeying, as well as can ensure that the average cost of rekeying is minimum even when adjusting Huffman key tree dynamically.