Windows CardSpace, is Microsoft's now-canceled client software for the Identity Metasystem. CardSpace is an instance of a class of identity client software called an Identity Selector. CardSpace stores references to users' digital identities for them, presenting them to users as visual Information Cards. CardSpace provides a consistent UI designed to help people to easily and securely use these identities in applications and web sites where they are accepted. Resistance to phishing attacks and adherence to Kim Cameron's "7 Laws of Identity" were goals in its design.
Overview
When an Information Card-enabled application or website wishes to obtain information about the user, the application or website requests a particular set of claims from the user. The CardSpace UI then appears, switching the display to the CardSpace service, which displays the user's stored identities as visual i-cards. The user selects the InfoCard to use and the CardSpace software contacts the issuer of the identity to obtain a digitally signedXML token that contains the requested information. CardSpace also allows users to create personal Information Cards, which can contain one or more of 14 fields of identity information such as full name, address, etc. Other transactions may require a managed InfoCard; these are issued by a third partyidentity provider that makes the claims on the person's behalf, such as a bank, employer, or a government agency. Windows CardSpace is built on top of the Web Services Protocol Stack, an open set of XML-based protocols, including WS-Security, WS-Trust, WS-MetadataExchange and WS-SecurityPolicy. This means that any technology or platform that supports WS-* protocols can integrate with CardSpace. In order to accept Information Cards, a website developer simply needs to declare an HTML<OBJECT> tag that specifies the claims the website is demanding from the user and then implement code to decrypt the returned token and extract the claim values. If an Identity Provider wants to issue tokens, they must provide a means by which a user can obtain a managed card and provide a Security Token Service which handles WS-Trust requests and returns an appropriate encrypted & signed token. If an Identity Provider does not wish to build an STS, they will be able to obtain one from a variety of vendors including PingIdentity, BMC, Sun Microsystems, Microsoft, or Siemens, as well as other companies or organizations. Because CardSpace and the Identity Metasystem upon which it is based are token-format-agnostic, CardSpace did not compete directly with other Internet identity architectures like OpenID and SAML. In some ways, these three approaches to identity can be seen as complementary. Indeed, Information Cards can be used today for signing into OpenID providers, Windows Live ID accounts, SAML identity providers, and other kinds of services. IBM and Novell planned to support the Higgins trust framework to provide a development framework that includes support for Information Cards and the Web ServicesProtocol Stack, thus including CardSpace within a broader, extensible framework also supporting other identity-related technologies, such as SAML and OpenID. Microsoft initially shipped Windows CardSpace with the.NET Framework 3.0, which runs on Windows XP, Windows Server 2003, and Windows Vista. It is installed by default on Windows Vista as well as Windows 7 and is available as a free download for XP and Server 2003 via Windows Update. An updated version of CardSpace shipped with the.NET Framework 3.5. In Windows 7 CardSpace technology is used by the new Credential Manager for the management and storage of saved user credentials.
Retirement
On February 15, 2011, Microsoft announced that Windows CardSpace 2.0 would not be shipped. Microsoft is currently working on a replacement called U-Prove.
