WebID

WebID gives one way to log in to an internet service. Instead of using a password, for example, the member refers to another web address which can vouch for it. WebID is not a specific service or product. Instead WebID is a suggested method for internet services and members to know who they are communicating with. Technically speaking, The WebID specifications define a set of proposed standards for Identity, identification and authentication on HTTP based networks.

A WebID is an HTTP URI that denotes ("refers to" or "names)" an agent on HTTP based networks e.g., the Web or an enterprise Intranet. In line with Linked Data principles, when you de-reference ("look up") a WebID, it resolves to a profile document that describes its referent (what it denotes). This profile document consists of RDF model based structured data, constructed initially using terms from the FOAF vocabulary, but now often including terms from other vocabularies.

Profile documents can be stored on the agent's own Web server, and access thereto may be partially or wholly constrained to specific agent identities via the use of access controls, to preserve the privacy of the profile document's subject.

The WebID+TLS protocol (formerly known as FOAF+SSL) is a decentralized and secure authentication protocol built upon the profile information as well as the Transport Layer Security (TLS) client certificates available in virtually all modern web browsers. It was first presented for the W3C Workshop on the Future of Social Networking in 2009.

Contrary to the usual SSL usage patterns, it does not require a dedicated Certificate authority to perform the user authorization. Users can easily mint useful identities for themselves using any TLS certificate (even self-signed ones). Using TLS client certificates for Web site user authentication doesn't usually require that the user input a password, unlike many other single sign-on mechanisms, which can make WebID+TLS quite convenient. However, the client certificate selection dialogues in popular Web browsers are not yet as user-friendly as they might be, negating some of this convenience.

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Wikipedia