分析了中国无线局域网标准中无线鉴别基础设施WAI(WLAN Authentication Infrastructure),指出其中密钥协商协议缺乏密钥确认、易遭受拒绝服务攻击等安全问题。提出了一种采用三次握手和带消息认证的密钥协商协议,以及周期密钥更新协议。使用BAN逻辑对提出的改进密钥协商协议进行形式化分析,验证了其正确性。与WAI比较,提出的协议具有较少的交互性,提供了消息鉴别并具有抗拒绝服务攻击能力。 This paper analyzes WLAN Authentication Infrastructure (WAI) in WLAN standard of China, and points out that the key agreement protocol lacks key confirmation and is vulnerable to security issues such as denial of service attacks. Proposed a three-way handshake and message authentication key agreement protocol, as well as periodic key renewal protocol. The BAN logic is used to formally analyze the proposed improved key agreement protocol, which verifies its correctness. Compared with the WAI, the proposed protocol has less interactivity, provides message authentication and has anti-denial of service attack capability.