When someone logs into a site using Open ID, what goes on behind the scene?
can someone explain to me the work flow/steps of what happens during a typical login from a partner open ID site? (like this site)
i.e. when I login at myopenid, what is passed into this site? how does SO know it was a correct login?
Also check out the Logging In section of the OpenID wikipedia entry. (You've probably already read it if you were following links in Jeff's article). :)
OpenID is an open, decentralized, free framework for user-centric digital identity. OpenID takes advantage of already existing internet technology (URI, HTTP, SSL, Diffie-Hellman) and realizes that people are already creating identities for themselves whether it be at their blog, photostream, profile page, etc. With OpenID you can easily transform one of these existing URIs into an account which can be used at sites which support OpenID logins.
The difference it's that the identification will be decentralized to an external site (example Wordpress, yahoo...). The website will know that the identification is ok or not and let you loggin.Conventional authentification form do a comparison to their private database and let you loggin or not. You can only use the loggin-password to this website. With openId you can use the same loggin-password on multiple website.
I wrote this answer for this question but this one is more old, so I pasted my answer over here.
