Research On Data Encryption And Access Authentication Mechanism In Wireless Local Area Network Security

WLAN(wireless local area network) is becoming people’s first choice as itsconvince access to internet, and high rate of transmission in the modern days. Inrecent years WLAN is becoming popular in many hot spot such as railway station，airport，shopping malls and so on. except the convince the WLAN provide, it alsobring many security problems. Because of the WLAN use electromagnetic wave asits transmission medium, and the medium has the character of open, the hacker cancapture the communication data packets in a certain distance，so the securityproblem of the WLAN has always been suspected. How to solve the problem ofsecurity communication in WLAN is the key technology restricting the WLAN’shealthy development. This paper mainly discusse WLAN’s security problem fromtwo aspects，the data encryption mechanism and security authentication accessaspect.In the aspect of data encryption， three encryption and decipheringmechanisms of protocol are discussed, including WEP protocol、WPA protocol andWPA2protocol. focusing on the point of the RC4algorithm in WEP protocoldefects，at the end of the chapter three a FMS attack has been finished successfullyand deciphered user’s password. The WPA and WPA2protocol in data encryptionare modified, remedied the WEP protocol vulnerabilities,the security problem is notexciting，but the access authentication mechanism which will reveal the user keyinformation，an attacker can launch a dictionary attack because of this loopholes.The user’s key complexity is another problem affect the security problem.In the aspect of access authentication, its focus on the4-way handshakeprotocol used in authentication，because of the loopholes in the4-way handshake，an attacker can easily launch an dictionary attack. In order to repair the defects inthe protocol two improved methods were proposed1.Anonce encryption methods； 2.message1integrate check method，and also the proposed methods securityproblem are discussed. For the lack of security and efficience problems in the4-way handshake，a new improved protocol is proposed–the2-way handshakeprotocol，and the new protocol’s security problem is also discussed，and theefficience is compared to4-way handshake protocol when be applied in the fasthandover mechanism.