自适应Huffman树组密钥更新方案

Adaptive Huffman tree scheme for multicast rekeying

利用Huffman树来实现组密钥更新具有平均更新开销最小的优势.针对现有方案中Huffman树只能静态创建,而无法动态调整的问题,提出了一种根据用户进出组的频率而动态调整的自适应Huffman树算法;同时,提出了自适应调整过程中的节点位置交换密钥更新算法,并给出了用户加入或离开时的组密钥更新算法.分析表明,该方案能保证组密钥更新的安全性,当用户进出组时,树的形状随着用户的进出而动态变化,并能始终保持Huffman树用户平均密钥更新代价最小.

Huffman key tree scheme has least average cost for multicast rekeying, but Huffman key tree can＇t be adjusted dynamically and be statically established in current scheme. An adaptive Huffman key tree scheme for multicast but rekeying was proposed in which the structure of Huffman key tree could be adjusted adaptively with the frequency of users joining in or leaving from multicast group before now, then rekeying arithmetic for node position exchange and member join or leave was proposed respectively. The analysis proved that the scheme can provide the security of multicast rekeying, as well as can ensure that the average cost of rekeying be minimum even when adjusting Huffman key tree dynamically.