Following the widespread use of the Internet, especially the World Wide
Web since 1995, wireless networking has become a buzz word at the beginning of
the new millennium. New terms such as wireless communications, wireless local
area networks (WLANs), wireless web, wireless application protocols (WAP),
wireless transactions, wireless multimedia applications, etc. have emerged and
become common vocabulary for computer and information professionals. Among the
emerging wireless technologies, WLANs have gained much popularity in various
sectors, including business offices, government buildings, schools, and
residential homes. The set of IEEE 802.11 protocols (especially 11a, 11b, and
11g), nicknamed wi-fi, have become
the standard protocols for WLANs since late 1990s.
Increasing number of 802.11 based WLANs have been deployed in various
types of locations, including homes, schools, airports, business offices,
government buildings, military facilities, coffee shops, book stores, as well
as many other venues. One of the primary
advantages offered by WLAN is its ability to provide untethered connectivity to
portable devices, such as wireless laptops and PDAs. In some remote communities,
WLANs are implemented
a viable last-mile technology 1, which link homes and offices in isolated
locations to the global Internet.
The further widespread deployment of WLANs, however, depends on whether
secure networking can be achieved. In order for critical data and services to
be 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 also
known to be easily cracked by common hacking software. WLANs having various
security issues such as eavesdropping, stealing of resources, chances of
service attacks, static WEP keys, absence of mutual authentication and session
hijack attack, etc. To establish a secure WLAN, it is necessary to implement an
alternat security mechanism, such as SSL, VPN, Wi-Fi Protected Access (WPA), or
the being-developed IEEE 802.11i protocols.
In this paper, the security aspects of WLANs are studied. We first give
an overview of the various types of WLANs and the respective vulnerabilities of
various protocols, followed by a discussion of alternative security mechanisms
that may be used to protect WLANs.