Windows CardSpace is client software that enables users to authenticate to a website or web service using information cards for added security. Information cards contain identity meta data and can be given to a user by an identity provider such as a bank, employer or government or created by the user themselves.

When the user chooses a card, a signed and encrypted security token containing the required information (e.g. name and address, employer’s name and address, or credit limit) is generated by the identity provider that created the card. The user can then decide whether to release this information to the requesting online service. If the user approves, a token is sent on to the third party where the token is processed and the identity information is extracted.

Today, the Live team has announced a practical use of this authentication method by introducing beta support to sign into Windows Live, MSN, Hotmail & Passport sites using a Windows Cardspace.

If you are using Windows Vista which has in built Cardspace support, visit Windows LiveID Information Card management page to create self signed information cards. Windows XP and 2003 users will need to download and install Microsoft .Net Framework 3.0 with cardspace support which the website would prompt anyway if it is not detected.

After creating your first information card, you will see the choice of Password or Information Card when you visit any Windows Live enabled website or service on the Internet.