The authentication in public WLAN when access controller deployed

Wireless connectivity ability in ´hot spots´ is becoming increasingly important now. Public wireless local area network (PWLAN) provides convenient high-speed access based on IEEE 802.11 standard to the Internet. The authentication scheme provided by IEEE802.11 standard was too weak to afford a practical authentication. Many solutions such as 802.11i standard draft have proposed to resolve these security problems in WLAN environment. But they are not practicable in PWLAN, because these solutions didn´t consider how to authenticate in the scene that an access controller was deployed to provide an Internet gateway between the wireless access network and the Internet. This paper proposes a new authentication scheme, which is suitable for this scene and also is compatible with 802.11i. From the security analysis, we can conclude that the scheme can offer an immediate and strong security solution for public environment.