一种 LKH 组播密钥树的启发式构建方法

摘要

LKH（logical key hierarchy）方法是一种有效的组播密钥更新技术。但在密钥更新过程中，该方法的加密开销与传输开销往往成为通信系统的瓶颈。通过对上述问题的研究，给出了最优密钥树结构的定义，并提出一种构建最优密钥树的启发式搜索算法。与传统 LKH 密钥树结构相比，最优树的不同层具有不同的分支数，因此其可降低密钥更新过程中的处理开销。理论分析与仿真实验均表明，所提方案可有效降低系统组播密钥更新的加密开销、传输开销及密钥存储量。%LKH method is an efficient multicast key update technology.But during the rekey process in this method,encryp-tion and transmission overhead often become a bottleneck in the communication system.Through the study of the above issue, this paper developed a heuristic search algorithm to construct an optimal key tree structure.Different from the traditional LKH key tree structure,the branching factor of this approach could take on different values at each level of tree,so the new struc-ture could reduce the rekey overhead.The experimental results show that the scheme can efficiently reduce the encryption overhead,transmission overhead and the storage of keys in the system during the rekey process.