Wired Equivalent Privacy, 64-bit or 128-bit Wi-Fi encryption. Provides limited protection for wireless LANs - cannot really be `wired equivalent` since radio-based systems present completely different security issues. However WEP can deter casual access. WEP keys must be manually updated for each user on the WLAN when a change is made, so WEP keys may not be updated often enough. WEP provides only one-way authentication, of the user to the access point, so a user cannot be sure if an access point is legitimate. WEP encrypts using the RC4 algorithm, which more vulnerable than other schemes such as triple DES - or AES as used in 802.11i.
... Found on http://www.encyclo.co.uk/visitor-contributions.php