Study Of The Secure Access Control Method Of Wireless Local Area Network (WLAN)

Since WLAN(Wireless Local Area Network)first appeared in 1990,some people had thought that a new age without wired limitation was coming.But, for many reasons, such as security, WLAN has a slower development than expected.The secure access control method of WLAN, is proposed on base of studying IEEE 802.11 and IEEE 802.11i protocols, to improve the security of 802.11 WLAN.This method theoretically describes a whole process of some wireless station's access to a WLAN, which includes three aspects composed of authentication, authority and key management.To testify the practicability of the secure access control method, there are two ways.One is a formalized analysis named BAN logic, and the other is a system simulation.BAN logic presented by Burrows, Abadi and Needham, is dependent on the reasoning rules, assumptions and inferences to find out some defects in some authentication protocols.By a series of analytic steps, the method is proved to have no obvious shortcomings.The system simulation brings up the state machines and frame formats of all reactions and communications among the four roles, i.e, a wireless station, an access point, an access control and an authentication server, when the wireless station joins into the WLAN administratored by the access point. The whole demostration consists of six parts which are probing net, 802.11 authentication, 802.11 association, 802.1x authentication, pairwise master key negotiation and group key distribution. Especially, ACE, a kind of toolkit programmed by C++ programming language, is adopted for concurrent pattern in the simulation.