关键词: 组安全通信, 贡献型组密钥管理, 逻辑密钥树

Abstract: 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) is presented to achieve better time efficiency. First, a new key tree topology comprised of main tree and join tree is put forward. Then, a new join algorithm in the join tree is proposed to reduce the time complexity. Last, optimal capacity of the join tree is selected through optimization method. Theoretical analysis and simulations show that the asymptotic average join time is reduced to, where is the group size.

Key words: Secure group communication, Contributory group key management, Logical key hierarchy