Among the first successful attempts to implement a thid-party authentication mechanism was the first release of OpenID, an open and decentralized authentication protocol promoted by the non-profit OpenID Foundation. Available since 2005, it was quickly and enthusiastically adopted by some big players such as Google and StackOverflow, who originally based their authentication providers upon it.
Here's how it works in a few words:
- Whenever our application receives an OpenID authentication request, it opens a transparent connection interface through the requesting user and a trusted, third-party authentication provider (for example, the Google Identity Provider); the interface can be a popup, an AJAX, populated modal ...
