What Is a Web of Trust?

Trust network (English: Web of Trust, abbreviation: WoT) is a concept in cryptography that can be used to verify the identity of the holder of a public key and is used in PGP, GnuPG, or other OpenPGP compatible systems.

The concept of trust network was first proposed by PGP author Phil Zimmerman in the PGP 2.0 user manual. A trust network is a network formed by the trust relationships of all users in the system. As shown in Figure 1, the trust network is a directed network. Each node in the network represents a user. Each edge represents the trust relationship between users, and the weight of the edge is the degree of trust. ^[1]

Trust networks use the concept of decentralization to replace the public key infrastructure that relies on digital certificate authorities. In computer networks, there can be many independent trust networks at the same time, and any user can be a part of these networks or a link between different networks.