中文摘要：

随着互联网的发展,多播技术被越来越多地应用在一些主流的服务中。例如,视频会议、IP电视、远程教育等。IP多播的安全性问题限制了其广泛使用,为了保护通信的机密性,在多播组中仅仅给予合格的组成员相应的密钥用于通信。密钥管理是IP多播的一个基本问题,密钥管理的目的是为了组成员在一个多播期间形成、更新、传输密钥,以及在传输过程中提供密钥的保密性。回顾了几种经典的密钥管理方法,并提出了一种基于LKH的分层式密钥更新的优化方案,最后与其他方法进行了比较。

英文摘要：

With the development of the Internet,multicast technology is used popularly in many mainstream applications.For example,video conferencing,IPTV,remote education.Security problems of IP Multicast limit its development,in order to protect the confidentiality of communications,multicast group only give the key to qualified members of the group for communication.Key management is a basic problem of the IP multicast,the aim of key management for multicast is forming keys during a multicast group session,update,transport keys,and providing the confidentiality.In this paper,we review several typical key management method,and propose a scheme which based on LKH hierarchical key optimization program,At last,we make a comparision between our method and others.