一种LKH组播密钥树的启发式构建方法

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。

A Heuristic Construction Method of LKH Multicast Key Tree

LKH method is an efficient multicast key update technology. But during the rekey process in this method, encryption 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 our approach could take on different values at each level of tree, so the new structure can reduce the rekey overhead. The experimental results showed the scheme can efficiently reduce the encryption overhead, transmission overhead and the storage of keys in the system during the rekey process.