A Survey of Trust - Computer Science and the Semantic Web

A Survey of Trust

in Computer Science and the Semantic Web

Donovan Artz and Yolanda Gil

Information Sciences Institute

University of Southern California

4676 Admiralty Way, Marina del Rey CA 90292

+1 310-822-1511

gil@isi.edu

March 15, 2007

Abstract

Trust is an integral component in many kinds of human interaction,

allowing people to act under uncertainty and with the risk of negative

consequences. For example, exchanging money for a service, giving access

to your property, and choosing between conflicting sources of information

all may utilize some form of trust. In computer science, trust is a widelyused

term whose definition differs among researchers and application areas.

Trust is an essential component of the vision for the Semantic Web, where

both new problems and new applications of trust are being studied. This

paper gives an overview of existing trust research in computer science and

the Semantic Web.

Keywords: Trust, Web of Trust, Policies, Reputation

To appear in Journal of Web Semantics: Science, Services and Agents on the World

Wide Web, 2007.

1 Introduction

Trust is a central component of the Semantic Web vision (Berners-Lee 1999; Berners-Lee et

al 2001; Berners-Lee et al 2006). The Semantic Web stack (Berners-Lee 2000; Berners-Lee et al

2006) has included all along a trust layer to assimilate the ontology, rules, logic, and proof layers.

Trust often refers to mechanisms to verify that the source of information is really who the source

claims to be. Signatures and encryption mechanisms should allow any consumer of information

to check the sources of that information. In addition, proofs should provide a tractable way to

verify that a claim is valid. In this sense, any information provider should be able to supply upon

request a proof that can be easily checked that certifies the origins of the information, rather