一种针对密钥树的密钥状态维护方案

群密钥的协商和管理是安全群组通信技术的核心。TGDH和DISEC方案是两类重要的分散凑份式群密钥协商方案。这两个方案的共同特点是都采用密钥树来管理和组织群密钥的协商进程。本文针对这两个方案的共同特点，设计了一个针对密钥树的密钥状态维护方案。该方案能够帮助群组通信系统的成员在复杂成员关系变化事件下，确定自己需要更新的节点密钥和盲节点密钥，从而为凑份式群密钥协商方案的实现提供了有效的同步机制。

THE KEY STATE MAINTENANCE OF TREE-BASED CONTRIBUTORY KEY AGREEMENT

The group key management or agreement is the core of secure group communication technology. TGDH and DISEC are two efficient and attractive contributory key agreement schemes. The common feature of TGDH and DISEC is that they all use key tree structure. In this paper, a key state maintenance scheme for these two contributory key agreement schemes is proposed, which can help group member find node keys and blinded node keys that need to be updated. According to key state information, group member will know when to start the group key agreement process and when to block it.