Trust Models

Abstract

Multi-agent systems consist of a large number of intelligent, interactive and (partially) autonomous agents that must cooperate to complete a certain task, often too difficult to solve for an individual agent. Such systems are used in a wide range of applications, ranging from mobile environments [73], over the creation of crowd-related effects for movies1, to online trading [57]. Multi-agent systems can often benefit from a trust system, especially when the circumstances do not allow for perfect information about the interaction partners’ behavior and intentions [117]. They may for example incorporate a trust network to monitor and control the behavior of the agents that participate in a process, think e.g. of an online market place such as eBay. Another nice illustration can be found in [66], in which a trust network is used to alleviate the problem of corrupt sources in peer-to-peer file-sharing networks by keeping track of the peers’ trustworthiness. With the advent of the Semantic Web [12], even more applications and systems will need solid trust mechanisms. The Semantic Web is an extension of the current web where content is annotated (see RDF2 and OWL3) such that machines and computers are able to understand its meaning and reason with it. Hence, since more and more intelligent agents will take over human tasks in the future, they also require an automated way of inferring trust in each other, see for instance [123].

Seldom, very seldom, does complete truth belong to any human disclosure; seldom can it happen that something is not a little disguised, or a little mistaken. Emma, 1815. Jane Austen