Аннотация
802.11i is the latest security protocol of WLAN, providing confidentiality, integrity and mutual authentication schemes. The paper analyzed the 4-way handshake mechanism of 802.11i protocol, and pointed out the weakness of 4-way handshake protocol flaws and possible attacks. Two improved mechanisms are proposed: 1. ANonce encryption, the transmission of plaintext of ANonce in the method is avoided and enhanced the message1's security. 2. Message1 integrity detection method, the method for messages 1 MIC verification, to ensure the integrity of the message 1. Finally analyzes the security of improvement mechanism.