Web of trust

A web of trust (wikipedia) is a network of key signatures. It has been used for a while with PGP to establish a decentralized trust network for encrypted communications and proof of authenticity. Duniter's web of trust aims to add unicity of digital identity (one person = one key) and to ensure frequent renewal of the signatures. This has several applications from Duniter-specific Universal Dividend and more general voting systems or proof of identity.


Here is some Duniter specific vocabulary and the equivalent in graph theory (wikipedia).

wordexplanationgraph equivalentdescription
identityliving person uniquely associated with a cryptographic keyvertex, node (wikipedia)node in the network
membershipfact for an identity for being part of the web of trust
certificationdated and cryptographically signed document assessing IRL trustedge, linkedge in the network
identity indegreenumber of certifications received by an identitynode indegree (wikipedia)number of links pointing towards a node
identity outdegreenumber of certifications emitted by an identitynode outdegree (wikipedia)number of links coming from a node
(in/out)neighborhood of a node (wikipedia)subgraph made of adjacent nodes (using only in/out links)


We can divide the rules of Duniter web of trust into static and temporal rules describing the state of a snapshot of the graph and the evolution of it along time.

This simplified version of the rules aim to give a global view. Additionnal detail can be found in the references.

Static rules

The static rules describe the graph properties we can observe on a snapshot of the web of trust.

The number of identities member of the web of trust is written N.

Dynamic rules

The dynamic rules describe the evolution of the web of trust along time.

Entry rule

In addition to the previous rules, an identity I must comply with the distance rule to enter the web of trust. The distance rule is defined as follows:

The distance rules applies on identity entry and membership renewal.


Duniter Ğ1 web of trust started on 2017-03-08 with 59 identities and 551 certifications at the block 0 of Duniter Ğ1 blockchain. As of 2023-09-25 it counts 8449 member identities and 98756 active certifications. This graph shows the evolution of the member count along time.

plot members along time

evolution of the member count along time
made with DataJune

We can see that part of the identities expire after not being renewed during the 1 year period. This ensures all the member identities are actively using their digital identity. It is possible to display the evolution of this web of trust using a force-directed layout.

web of trust snapshot

snapshot of the web of trust (2022-11-22)
animation is visible on https://youtu.be/Hj3GpaEYLwA