The update was originally announced in early April but only appeared on the Microsoft Download Center over the weekend.
Microsoft said the patch also contains support for WPS/IE (Wireless Provisioning Services Information Element), the protocol that handles the distribution of configuration and service information to a wireless client.
It replaced the stopgap WPA (Wi-Fi Protected Access) protocol and offers a more advanced encryption technique called AES (Advanced Encryption Standard).
By adding support for WPA2, Microsoft can now market Windows XP Service Pack 2 with full FIPS 140-2 (Federal Information Processing Standard – Publication 140-2) support. FIPS 140-2 is a U.S. security standard used to certify cryptographic modules and is mandatory for some businesses.
According to a knowledge base article, users that download the Windows XP patch will be able to view previously hidden SSIDs (Service Set Identifiers) in the "Choose a Wireless Network" dialog box. This functionality simplifies the users connection to public Wi-Fi networks that were not previously connected.
Microsoft said the WPA2/WPS IE Update supports several features of WPA2, including:
- WPA2 Enterprise using IEEE 802.1X authentication and WPA Personal using a PSK (preshared key).
- The AES using the CCMP (Counter Mode-Cipher Block Chaining-Message Authentication Code Protocol) that provides data confidentiality, data-origin authentication and data integrity for wireless frames.
- The optional use of PMK (Pairwise Master Key) caching and opportunistic PMK caching, allowing faster access when a wireless client roams back to a wireless access point to which the client has already authenticated.
- The optional use of pre-authentication to allow a WPA2 wireless client to perform an 802.1X authentication with other wireless access points in its range when it is still connected to its current wireless access point.