I. IntroductionFollowing the widespread use of the Internet, especially the World WideWeb since 1995, wireless networking has become a buzz word at the beginning ofthe new millennium. New terms such as wireless communications, wireless localarea networks (WLANs), wireless web, wireless application protocols (WAP),wireless transactions, wireless multimedia applications, etc. have emerged andbecome common vocabulary for computer and information professionals. Among theemerging wireless technologies, WLANs have gained much popularity in varioussectors, including business offices, government buildings, schools, andresidential homes.
The set of IEEE 802.11 protocols (especially 11a, 11b, and11g), nicknamed wi-fi, have becomethe standard protocols for WLANs since late 1990s. Increasing number of 802.11 based WLANs have been deployed in varioustypes of locations, including homes, schools, airports, business offices,government buildings, military facilities, coffee shops, book stores, as wellas many other venues. One of the primaryadvantages offered by WLAN is its ability to provide untethered connectivity toportable devices, such as wireless laptops and PDAs.
In some remote communities,WLANs are implemented asa viable last-mile technology 1, which link homes and offices in isolatedlocations to the global Internet. The further widespread deployment of WLANs, however, depends on whethersecure networking can be achieved. In order for critical data and services tobe distribute over WLANs, reasonable level of security must be guaranteed. The WEP (Wired Equivalent Privacy)protocol, actually proposed for the security mechanism of 802.11 WLANs, is alsoknown to be easily cracked by common hacking software.
WLANs having varioussecurity issues such as eavesdropping, stealing of resources, chances ofservice attacks, static WEP keys, absence of mutual authentication and sessionhijack attack, etc. To establish a secure WLAN, it is necessary to implement analternat security mechanism, such as SSL, VPN, Wi-Fi Protected Access (WPA), orthe being-developed IEEE 802.11i protocols.In this paper, the security aspects of WLANs are studied.
We first givean overview of the various types of WLANs and the respective vulnerabilities ofvarious protocols, followed by a discussion of alternative security mechanismsthat may be used to protect WLANs.