Early analog cellular phone systems were vulnerable to eavesdropping. As a result the adoption of that technology was not as fast as it might have been had good security been implemented by service providers. Vo802.11 must overcome any user anxieties regarding security on the network. Fears of eavesdropping and fraud can dampen consumer enthusiasm for the service. This chapter describes security measures for 802.11 networks and provides an assessment of the difficulty of "hacking" or otherwise compromising the security of 802.11 networks.

Unlike wired systems, which can be physically secured, wireless networks are not confined to inside buildings, but can be picked up as far as 1,000 feet outside of the premises with a laptop and a gain antenna. This makes WLANs inherently vulnerable to interception. Knowing this, the 802.11 committee added a first line of defense called Wireless Equivalency Protocol. WEPisan encryption protocol that is designed to provide the same level of security that wired cables provide. The standard provides both 40- and 128-bit (really only 104-bit) encryption at the link layer using the RC4 algorithm, which the U.S. government allows to be exported.

Electronics retailer Best Buy Co. ran into trouble in mid-2002 when customers who had purchased WLAN cards from Best Buy installed the cards in their laptops before they left the parking lot. The customers noticed unencrypted WLAN traffic that contained customer information and possibly credit card numbers. The Best Buy case provides an example of why enterprises should at a minimum encrypt their...