You’ve logged onto Gmail, and then you go over to Facebook — where you’re already logged in and your Gmail personal information is automatically available. That kind of portable identity became possible Monday as Facebook announced it has become a “relying party” for the OpenID user-identity framework.
Yahoo, AOL, MySpace and Microsoft also support OpenID. But while others are “issuing parties,” Facebook is now a relying party. Issuing parties let you use their OpenID log-in elsewhere, but they don’t necessarily accept it from other sites, as relying parties do.
This means you can log in to Gmail and then go to Facebook and find yourself already on board. But you can’t log in to Yahoo, for example, and find yourself already logged in to Gmail.
These kinds of one-way streets can lead to confusion about OpenID, and observers have suggested that the standard needs more uniformity before it becomes easy to understand.
OpenID Foundation Member
In theory, OpenID not only allows data like your profile information to be available on all OpenID-compatible sites, but it also minimizes the number of usernames and passwords a Web user needs to remember.
Facebook already has its own portable-identity service, called Facebook Connect, and it allows users to log in to other sites with their Facebook identities. With support for OpenID, the two competing protocols are now closer to unification, opening up the possibility of a single log-in and portable identity across many sites.
As the largest social-networking site with about 200 million members, Facebook’s participation is a big step in that direction.
The company has been a member of the OpenID Foundation since the winter, and has hosted a summit conference about OpenID. On the company’s developers blog, Facebook’s Luke Shepard wrote Monday that the company has been using its experience in…