安全组播密钥管理的层次结构研究

组播是面向组接收者的有效数据通信方式，其重要性正日益突出，组管理协议(IGMP)不提供成员接入控制，为保护通信机密性，安全组播使用不为组外成员所知的业务密钥来加密数据，并随组成员关系变化而动态更新，密钥管理成为安全组播研究的核心问题，为支持大规模安全组播，引入了逻辑密钥层次结构，以使密钥管理具有可扩展性，在对逻辑密钥层次作具体分析的基础上，本文就密钥树最优结构问题作了理论上的探讨，并取得了与实验一致的结论。

Hierarchical Key Management in Secure Multicast

Multicast is a preferred communication technique in multiple recipients and its importance is rapidly growing. The Internet Group Management: Protocol(IGMP) does not provide access control of the members. To provide communication confidentiality, traffic in secure multicast is encrypted with a session key known only by certified group members. Whenever there is a change in the group membership, the key has to be updated dynamically, thus key management is indicated as the sticking point in secure multicast research. To be applicable to large scale multicast, hierarchical structure is introduced as a solution to the scalability problem of group key management. The paper addresses the logical key hierarchy and concentrates on the optimal structure problem of the key tree. A theoretical analysis is given in the paper with the result in correspondence with a previous experimental conclusion.