Abstract: Recently, there are many group communication applications which ensure group members have multiple access privilege. The accesscontrol of these applications should provide the members that subscribe different services the ability of obtaining different sets of data. This paperpresents a multi-group access control scheme that achieves multi-privileged access by combining the centralized and distributed key managementscheme. Compared with existing control scheme, the proposed scheme significantly reduces the communication, computation overhead and providesbetter adaptability.

Key words: Key management; Multi-privileged access; Forward encryption; Backward encryption

摘要： 现在的网络环境中，很多通信应用需要组成员拥有多层次的访问权限。这些应用的访问控制要保证拥有不同层次服务的用户能获得不同的数据。该文提出了一种多重组的访问控制方案，该方案使用集中式与分布协同式相结合的密钥更新算法实现了多权限的控制。与现存的方案相比，该文所述方案显著地减少了通信量和计算量，并拥有更好的适应性。

关键词: 密钥管理；多权限访问；向前加密；向后加密