摘要： 广播加密方案是一种应用广泛的群组通信方案，在视频音频网络直播、视频会议和证券实时行情发布等场合具有良好的应用前景。该文分析了4 种广播加密方案，在分析的基础上提出了一个改进的广播加密框架和改进后的方案。新方案具备用户扩展能力，并且在消息长度上和同等用户规模的现有方案相仿。

关键词: 广播加密；预留节点；注记

Abstract: Broadcast encryption communication is a wildly used group communication mode. The paper concisely analyses four typical protocols. A new broadcast encrypt frame and scheme are proposed. This scheme has the abiliity of user scalable, and its message length is similar with other schemes.

Key words: Broadcast encryption; Preserved node; Note