Basic Security Features

Obviously, one of the most important considerations when using a wireless LAN is security. An identifier called the Service Set ID (SSID), which is simply a network “name” (alphanumeric characters), is sometimes considered secret. The SSID can typically be found by “sniffing” the network. Sniffing for wireless traffic is just like sniffing on a wired network, but the medium is different. Whereas with traditional network sniffing you are catching data on a wire, in wireless sniffing, you are catching data that is going through the air as radio waves.

Note that no physical network exists to control or protect. With wireless networks, it is much more difficult to control and protect the air that your data is flowing through. The very nature of this type of network lends little to securing a network.

The next level of security is typically Wired Equivalent Privacy (WEP), which is essentially encryption. The principal goal of WEP is to defend the confidentiality of data from eavesdroppers. Another objective is to guard against modification of data. WEP depends on a secret key shared between the communicating parties (mobile station and AP) to protect the data portion of a transmitted frame in each direction. With WEP, although the data portion of the packet might be encrypted, the SSID network name and the MAC addresses are broadcast in the clear.