Wireless networks have a number of security issues. Signal leakage means that network communications can be picked up outside the physical boundaries of the building in which they are being operated, meaning a hacker can operate from the street outside or discretely from blocks away. In addition to signal leakage, the wired equivalent privacy protocol is inherently weak, and in addition to WEP’s weaknesses, there are various other attacks that can be initiated against WLANs, all with detrimental effects. On the surface WLANs act the same as their wired counterparts, transporting data between network devices. However, there is one fundamental, and quite significant, difference: WLANs are based on radio communications technology as an alternative to structured wiring and cables. Data is transmitted between devices through the air by utilizing the radio waves. Devices that participate in a WLAN must have a network interface card (NIC) with wireless capabilities. This essentially means that the card contains a small radio device that allows it to communicate with other wireless devices within the defined range for that card, for example, the 2.4-2.4853 GHz range. For a device to participate in a wireless network, it must firstly be permitted to communicate with the devices in that network, and secondly it must be within the transmission range of the devices in that network. To communicate, radio-based devices take advantage of electromagnetic waves and their ability to be altered in such a manner that they can carry information, known as modulation (Sundaralingham, 2004). Here we discuss wireless security mechanisms.