Microsoft Adds WPA2 WLAN Security To Windows XP
Specifically, Microsoft posted a support memo explaining the update and a link to download the update. The update itself, which is dated April 29, is for Windows XP Service Pack 2.
The most significant part of the update is support for WPA2, a strong WLAN security standard that was approved last year and that is being widely adopted in enterprises. WPA2 was a significant part of the 802.11i WLAN security standard.
WPA2 replaces the discredited WEP and supports 802.1X authentication and Advanced Encryption Standard (AES). It also supports optional use of Pairwise Master Key (PMK) caching and pre-authentication, which enables a wireless client such as a laptop to pre-authenticate with a wireless LAN when it still connected to another wireless LAN.
In addition, the update includes support for Wireless Provisioning Services Information Element (WPS IE), which simplifies logging on to public wireless networks such as hotspots. WPS IE solves the problem that most access points at public hotspots only allow transmission of a single Service Set Identifier (SSID).
As a result, Windows XP clients could not previously "see" a secondary SSID, which meant that users sometimes could not log on to hotspots that they previously were not connected to. This update solves that problem.