针对Diffie—Hellman协议易遭受中间人攻击的缺陷,文章采用共享口令和随机化的方式进行身份认讧,提出了一种基于口令的D—H密钥协商协议。通过对Byun和Lee的基于口令的群密钥协商方案及胡红宇的改进方案进行分析,发现改进后的协议存在不完整认证,会遭到篡改。文章首先对相关方案进行改进和完善,并在此基础之上,结合所改进的D—H密钥协商协议,基于椭圆曲线构造了一种在认证中传递消息的群密钥协商协议。
Diffie-Hellman protocol is vulnerable to man-in-the-middle attack, this paper proposes a password- based DH key agreement protocol using shared passwords and randomized manner authentication, By studying Byun and Lee's password-based group key agreement scheme and HU's improvement for it, This paper finds that the improved protocol has not complete certification and it would be tampered with.This article first improves and perfects the relevant programs and on this basis, combining with the improved DH key agreement protocol and basing on elliptic curve, constructs a group key agreement protocol in which the delivery message can be get in the certification.