摘要： 广播加密技术是一种安全群组通信的技术，在付费电视、电话会议、数字内容的网络发布等领域有广泛应用。在对现有广播加密机制进行比较和分析的基础上，该文提出了一种广播加密机制的用户端扩展方法，通过逻辑密钥树的再生长，解决了子集差分机制/分层子集差分机制无法扩展用户端的问题，可以在不影响系统原有用户的预分配密钥和解密处理的基础上，动态批量地扩展系统的用户端。

关键词: 广播加密, 子集差分, 分层子集差分

Abstract: Broadcast encryption can allow a center to broadcast secure transmission to an arbitrary set of recipients, which is popular in pay TV, telephone conference and so on. Based on the comparison and analysis of the existing broadcast encryption schemes, this paper proposes a broadcast encryption tree’s regrowth method. By making the logical key tree grow bottom-up, this method can add new users in batches without influencing the previous users. So it solves subset and layered subset difference scheme’s unscalability.

Key words: broadcast encryption, subset difference, layered subset difference

中图分类号: 

• TP309