IEEE 802.11i-2004

IEEE 802.11i-2004 or 802.11i, implemented as WPA2, is an amendment to the original IEEE 802.11. The draft standard was ratified on 24 June 2004. This standard specifies security mechanisms for wireless networks. It replaced the short Authentication and privacy clause of the original standard with a detailed Security clause. In the process it deprecated the broken WEP. The amendment was later incorporated into the published IEEE 802.11-2007 standard.

A major security flaw was revealed in December 2011 that affects wireless routers with the Wi-Fi Protected Setup (WPS) feature, which most recent models have and enable by default. The flaw allows a remote attacker to recover the WPS PIN and, with it, the router's WPA2 password in a few hours. Users have been urged to turn off the WPS feature, although this may not be possible on some router models.