Wired Equivalent Privacy (WEP) is a security technique for IEEE 802.11 wireless networks. It was incorporated in the first 802.11 standard, adopted in 1997, with the objective of ensuring data confidentiality comparable to that of a wired network. WEP was formerly popular and was usually the first security option provided to consumers by router configuration programs. WEP contains a key of 10 or 26 hexadecimal digits (40 or 104 bits).

In 2003, the Wi-Fi Alliance announced that WEP had been phased out in favor of Wi-Fi Protected Access (WPA) (WPA). When the full 802.11i standard (i.e. WPA2) was adopted in 2004, the IEEE declared both WEP-40 and WEP-104 obsolete. Prior to the WPA standard, which was only accessible for 802.11g devices, WEP was the only encryption method available for 802.11a and 802.11b devices. Later firmware or software upgrades enabled WPA on certain 802.11b devices, while newer devices came with it pre-installed.