Yeah -- I think you just described OpenID (not OAuth).
And to be honest, this is part of the problem. We use confusing (and sometimes conflicting) terminology to describe both authentication (identifying somebody) and authorization (making sure you have the right permissions to do something).
And to be honest, this is part of the problem. We use confusing (and sometimes conflicting) terminology to describe both authentication (identifying somebody) and authorization (making sure you have the right permissions to do something).
More information: https://stackoverflow.com/a/1087071/19020