The Web is a nickname for the World Wide Web, which refers both to the interconnected group of Internet sites that are linked by hypertext and also to all the documents on all Internet servers using the HTTP protocol (HyperText Transfer Protocol). Digital identity is generally ascertained by an online credential. Companies employ dated digital certificates issued by a CA (Certified Authority), that is, a trusted third party, as part of the Public-Key Encryption system, which verifies a user’s identity and allows secure communication on the Internet. The Web of Trust (WOT) is another mechanism for verifying digital identity on the Internet. It is an informal mechanism that relies on trust rather than authority.
In the Web of Trust as conceived as a mechanism for PGP (Pretty Good Privacy) by its creator Phil Zimmermann, there is no central authority to vouch for identity. Instead, a user with a new public key finds someone with a pair of keys, public and private, and asks that person to be their signer. The signer is meant to verify the identity of the person with the new public key in some indisputable way, for example, a face-to-face meeting. The other step prior to signing the key is to make sure that the key fingerprint in the key is correct, and once signing is complete, the signed key may be posted to key servers. People who trust in the signer and believe that he or she properly identified the public key owner and verified the key fingerprint can then choose to extend their trust to the keys that person has signed.
To make up for the fact that the signers in the system are amateurs, the Web of Trust requires multiple signers. The concept is that with multiple, independent signers, there is a better chance of avoiding the misjudgment or flawed process of any single signer. Rather than the World Wide Web or the growth of trust growing in a weblike fashion, the “web” reference is to the multiplicity of signers vouching for each certificate, creating a web of certitude.
Web of Trust is also a Firefox browser add-on. It is aimed at helping users avoid online scams including phishing attempts, spyware, viruses, adware, identify fraud, adult content, and spam. The company, that makes it, WOT, also offers the WOT Trust Seal, meant to be the sign of a reputable website.