Would anyone happen to know the terminology for using "multi-staged authentication", where each stage grants a specific level of authorization?
The concept is that you for instance browse a web page, not identifying and authenticating and you have a Level 0 in authorization.
At some point you wish to perform an action that needs authorization, thus you authenticate with a username and a password (or an OAuth token or some such), and you now have authorization Level 1.
Now you wish to perform a privileged action, which on this particular site requires you to perform 2-factor authentication. You request the action and an authentication mechanism requests you input, which you grant and you are now at authorization Level 2.
Whether this applies to just the action or whether your authorization profile for the session now is altered for the rest of the interactions is inconsequential - to this question. (If you have a good idea as to what would be better/easier/more secure, please feel free to answer that too)
What is this "multi-staged authentication" called? Do anyone know of an actual terminology for this? I may just have failed my Google classes, but could someone throw me a valid and accepted terminology for a similar application?
-- So to add a few of the answers here that I have partly mentioned in comments: OASIS Trust Elevation and IBM Step-up authentication from the accepted answer