Wi-Fi Protected Access (WPA) is a security standard for users of computers equipped with Wi-Fi wireless connection. It is an improvement on and is expected to replace the original Wi-Fi security standard, Wired Equivalent Privacy (WEP). WPA provides more sophisticated data encryption than WEP and also provides user authentication (WEP's user authentication is considered insufficient). WEP is still considered useful for the casual home user, but insufficient for the corporate environment where the large flow of messages can enable eavesdroppers to discover encryption keys more quickly.
WPA's encryption method is the Temporal Key Integrity Protocol (TKIP). TKIP addresses the weaknesses of WEP by including a per-packet mixing function, a message integrity check, an extended initialization vector, and a re-keying mechanism. WPA provides "strong" user authentication based on 802.1x and the Extensible Authentication Protocol (EAP). WPA depends on a central authentication server such as RADIUS to authenticate each user.
Wi-Fi Protected Access is a subset of and will be compatible with IEEE 802.11i (sometimes referred to as WPA2), a security standard under development. Software updates that will allow both server and client computers to implement WPA are expected to become widely available during 2003. Access points (see hot spots) can operate in mixed WEP/WPA mode to support both WEP and WPA clients. However, mixed mode effectively provides only WEP-level security for all users. Home users of access points that use only WPA can operate in a special home-mode in which the user need only enter a password to be connected to the access point. The password will trigger authentication and TKIP encryption.