Hierarchical Key Management in Secure Multicast
安全组播密钥管理的层次结构研究

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.