To provide content protection in large groups with highly dynamic memberships, a secure group key management efficient in key establishment and update is the foundation. In this paper, a join-tree-based contributory group key management (JDH) was presented to achieve better time efficiency. First, a new key tree topology comprised of main tree and join tree was put forward. Then, a new join algorithm in the join tree was proposed to reduce the time complexity. Last,optimal capacity of the join tree was selected through optimization method. The theoretical analysis and simulations show that the asymptotic average join time is complexity reduced to 0(1).%在大规模动态群组中,一个高效的能实时更新的组密钥管理算法是提供组通信内容保护的前提.提出了一种基于加入树的分布式组播密钥管理方案JDH.首先给出了一个包含主树和加入树的新型树形结构.其次,为了降低成员加入时的时间复杂度,给出了一种新的加入算法.最后,根据最优化方法选取了最优的加入树的大小.理论分析和仿真表明,JDH将成员加入时密钥更新的时间复杂度降低为O(1).
展开▼