Abstract: Group Key Agreement（GKA） protocol plays a key role in the construction of secure multicast channels. Because of the simplicity and efficiency of public key management, the ID-based Authenticated Group Key Agreement Protocol（AGKA） cryptosystem has become a hot research direction in recent years. This paper proposes a new Weil pairing and completely trigeminal tree based group key agreement protocol, designs the participants join-and-leave pre-protocol. Security analysis and performance analysis show that the new scheme satisfies all known security requirements. Compared with the existing schemes, the new scheme has obvious advantages in terms of performance.

Key words: Group Key Agreement（GKA）, ID-based authentication, Weil pairing, trigeminal tree

摘要： 群密钥协商（GKA）协议在构建安全多播信道中扮演着主要角色。由于公钥管理的简洁性和高效性，基于身份的认证群密钥协商协议密码系统近年来成为热门研究方向。提出了一个基于Weil对和完全三叉树结构的群密钥协商协议，同时提出了成员加入和离开子协议。对新方案的安全性进行了分析，结果显示，新方案可以抵抗常见的攻击。在性能方面，新方案在参与者较多时有较明显的计算优势。

关键词: 群密钥协商, 基于身份的认证, Weil对, 三叉树