User-centric identity infrastructure just took another key step forward today: Janrain, Sxip, Verisign, and Microsoft announced they will all be working together to help OpenID users get the benefits of CardSpace and vice versa. Links to the blog announcements:

• Kim Cameron, Microsoft
• Scott Kveton, Janrain
• Dick Hardt, Sxip
• Michael Graves, Verisign

I’m very happy to see this step for all the reasons I’ve been blogging recently:

• OpenID is about user-centric identity services that are possible because OpenID turns the user (or any entity with an OpenID identifier) into a first-class addressable endpoint on the net, with a standardized, lightweight service discovery mechanism (XRDS).
• CardSpace is about secure cross-domain authentication and exchange of both first-party and third-party claims.
• OpenID can use CardSpace’s security and anti-phishing protection — every website that accepts OpenID can leverage the use of CardSpace-protected logins at the user’s OpenID provider.
• CardSpace can use OpenID’s privacy-protected digital identifiers and lightweight service discovery, making information cards more dynamic and actionable to CardSpace relying parties.
• There has never been any need for the two technologies to compete on authentication. We need the strongest authentication we can get, as widely as we can get it, as soon as we can get it. Once that’s in place we can finally begin building new applications on top of the identity layer.

The devil’s always in the details, but let’s nail down the details on this one and get these two technologies working together ASAP.