简单认证密钥协商协议的学习与研究

Study and Research on Simple Authenticated Key Agreement Protocol

1999年Seo及Sweeney两位学者修改了著名的Diffie-Hellam密钥协议以提供用户身份认证,从而提出了简单认证密钥协商协议(SAKA)。但Sun却指出SAKA算法存在三处严重缺陷:(1)不能确认某个用户的身份;(2)不能防御密码猜测攻击;(3)不能提供完美前向安全性(PFS)。为了克服SAKA算法的缺陷,Tseng,Wang等人对该协议做出了一些改进。本文通过分析,指出了这些协议存在安全缺陷的根本原因并证明了其并不能有效抵制在线密钥猜测攻击。针对这些协议无法保证其安全性的不足,本文提出了一个改进方案,能够有效防止中间人攻击并提高计算效能。

In 1999,the two famous scholars,Seo and Sweeney,revised the well-known Diffie-Hellan Key Agreement to offer user authentication which is a simple authenticated key agreement(SAKA).But Sun pointed out that there are three deficiencies in SAKA:(1) cannot validate some user’s identity;(2) cannot defense password guessing attack;(3) Cannot provide perfect forward security.To overcome the deficiencies,Tseng and Wang improved the agreement.This paper explained primary causes of deficiencies in SAKA and Proposed improved scheme which can effectively prevent the attack by others and improve the computational efficiency based on the analysis of the deficiencies.