一种三方认证密钥协商协议的分析与改进

大多数三方认证密钥协商协议不能抵抗中间人攻击。为此，对Tan提出的三方认证密钥协商协议(Journal of Communications, 2010, No.5)进行分析，证明其不能抵抗发起者假冒攻击、响应者假冒攻击及中间人攻击，并利用单向哈希函数和椭圆曲线密码学技术对协议进行改进。理论分析与形式化证明结果表明，改进协议继承了原协议的安全性，并能抵抗假冒攻击及中间人攻击。

Analysis and Improvement of a Three-party Authenticated Key Agreement Protocol

Most Three-party Authenticated Key Agreement(3PAKA) protocols are susceptible to man-in-the-middle attack. This paper analyzes security of the 3PAKA protocol presented by Tan, and proves that it can not withstand counterfeit attacks and man-in-the-middle attack. To enhance its security, an improved protocol is proposed by one-way hash function and elliptic curve cryptography. Security analysis and formal proof results show that the improved protocol inherits the security of the original protocol, and is able to resist counterfeit attack and man-in-the-middle attack.