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Microsoft Using Cloud To Enable Single Sign-On in Windows 8

• By Kurt Mackie
• 09/26/2011

Windows Live will be a key element in Windows 8's roaming and single sign-on capabilities, Microsoft recently revealed.

A "developer preview" version of Windows 8 surfaced earlier this month during the Build conference, but the OS may not become generally available for another year or two. At any rate, it appears that with Windows 8, Microsoft is edging toward the world of connected devices championed by its former chief software architect, Ray Ozzie. Playing a key role in vision will be Windows Live.

Windows Live IDs are already used across Microsoft's TechNet and MSDN sites as a kind of master password, enabling access to various Microsoft Web sites. On the consumer side, Windows Live IDs are used to connect consumers using Windows Live Essentials applications and Office Web Apps. Users with Windows Live IDs get access to 25 GB of storage space for their files via Microsoft's SkyDrive cloud service. Microsoft Xbox Live users connect to Microsoft's gaming console services via Windows Live. Windows Phone 7.5 "Mango" users will have access to Windows Live SkyDrive service for photo storage and sharing.

Now, Windows 8 will let users sign on to their computer using a Windows Live ID, which will save Windows settings with the user account. Application and last-used state settings will then persist across other devices running Windows 8, according to Katie Frigon, a Microsoft group program manager on the "you-centered" experience team, in a blog post. Any changes to those settings are kept in sync via Microsoft's cloud. Users have control over what gets synced in terms of personalization, themes, language preferences and a few other matters.

If a device is used for work, IT pros have control over what can be synced via Group Policy settings. They can choose whether or not to link a domain account to a Windows Live ID. If the domain is linked, IT pros can control what data the user can access on the corporate network. Corporate credentials for a domain-joined PC will stay on the PC and aren't uploaded to the cloud, Frigon stated.

User profile data is protected through encryption on the client before being sent to the cloud via SSL/TLS, Frigon explained. By default, Microsoft does not allow such data to roam over a wireless wide area network. 

At Build, Microsoft described how developers can take advantage of Windows Live identity data, which can be used by applications. Windows Live identity data can be used by any application or Web site that supports the Windows Live login ID -- not just Microsoft's sites and apps, according to Dare Obasanjo, a Microsoft senior program manager. By using a Windows Live ID, users get a "zero click sign-in" experience across Web sites, Obasanjo explained in a Microsoft Build talk, "Power Your App With Live Services."

The second benefit to using a Windows Live ID with Windows 8 is its roaming support. Core ID settings get synced up to the Windows Live cloud, allowing users to use an app at work and pick up from where they left off at home. Obasanjo gave an example of an RSS newsreader application. Users can read articles at work and then pick up at home from where they left off via this syncing capability.

On the consumer end, the synchronization enable by Windows Live IDs will connect the various applications in the Windows Live Essentials suite, which is available as a free download for Windows users. For instance, the Windows Live Essentials Mail app can connect and synchronize multiple e-mail accounts, while the Calendar app can integrate multiple calendars such as those used at home and work, according to Chris Jones, vice president of Windows Live engineering, in a blog post.

Developers can get more information about how to connect Windows Live users to their apps via "Live Connect," a portal for Windows applications developers.