OpenID

OpenID Authentication provides a way to prove that an end user controls an Identifier. It does this without the Relying Party needing access to end user credentials such as a password or to other sensitive information such as an email address. OpenID is decentralized. No central authority must approve or register Relying Parties or OpenID Providers. An end user can freely choose which OpenID Provider to use, and can preserve their Identifier if they switch OpenID Providers. While nothing in the protocol requires JavaScript or modern browsers, the authentication scheme plays nicely with "AJAX"-style setups. This means an end user can prove their Identity to a Relying Party without having to leave their current Web page. OpenID Authentication uses only standard HTTP(S) requests and responses, so it does not require any special capabilities of the User-Agent or other client software. OpenID is not tied to the use of cookies or any other specific mechanism of Relying Party or OpenID Provider session management. Extensions to User-Agents can simplify the end user interaction, though are not required to utilize the protocol. The exchange of profile information, or the exchange of other information not covered in this specification, can be addressed through additional service types built on top of this protocol to create a framework. OpenID Authentication is designed to provide a base service to enable portable, user-centric digital identity in a free and decentralized manner.