Brian Matthews, DeFINE, Pisa 26/11/02 Trust and the Semantic Web Brian Matthews, Business & Information Technology Dept, CLRC

Brian Matthews, DeFINE, Pisa 26/11/02 Who are we? Multidisciplinary Science Laboratory Information Science & Engineering, Business & Information Technology Department –Advanced development of Business Information Systems –Research programme in information technology and distributed systems –Metadata, Trust, Grids, Workflow, Risk Analysis, Ambients …. Deputy Manager, W3C Office for the UK and Ireland

Brian Matthews, DeFINE, Pisa 26/11/02 Trust Working Definition: Trust of a party A in a party B for a service X is the measurable belief of A that B will behave dependably for a specified period within a specified context A property of intelligent agents A measure of the Dependability of others (including self) –can be used to determine behaviour Can be influenced by the –Recommendations of others (trust propagation) –Behaviour over time of other agents (experience) –The environment (regulatory, legal, benevolence etc).

Brian Matthews, DeFINE, Pisa 26/11/02 iTrust FP5 WG Looking at all aspects of Trust in open distributed systems –Policy management –Contract management –Risk Management –Links to security, dependability,privacy, ratings etc. Multidisciplinary –Computer science –Lawyers –Psychology –Philosophers –Management consultancy

Brian Matthews, DeFINE, Pisa 26/11/02 Establishing that the interactions between actors on the Web are trustworthy –Security: access control, authentication and authorisation and policies –Reliability and dependability –Quality ratings –Personalisation: Privacy, confidentiality, user preferences, accessibility –IPR Dynamic virtual organisations over Trusted Web Services –Transferring trust from third parties –Establishing service-level agreements which can be relied upon Establishing trust between agents that have no prior knowledge of each other Could prevent the growth of future wide area distributed systems Trust on the Web

Brian Matthews, DeFINE, Pisa 26/11/02 Semantic Web: Add Meaning to Resources

Brian Matthews, DeFINE, Pisa 26/11/02 A Layered Architecture

Brian Matthews, DeFINE, Pisa 26/11/02 Semantic Web – current status The Semantic Web has been around several years: –Base technologies well-established –Gone through several iterations –Lots of academic interest –Convincing applications are still missing However, many demonstrators and interesting applications. –CC/PP, P3P, PICS – applications of great significance to the trust domain. –Need to demonstrate the benefit of a common framework.

Brian Matthews, DeFINE, Pisa 26/11/02 SWAD-Europe Semantic Web Advanced Development in Europe Purpose is to encourage the use of Semantic Web tools and techniques now: –By an outreach programme –By developing practical demonstrators –By providing tools and standards Many application and demonstration areas –Annotations, querying, scalability, knowledge management, accessibility, web service integration –Developing tools and techniques for representing and processing Trust relationships in the Semantic Web. Partners: –Univ. of Bristol, W3C-INRIA, CCLRC, HP Labs, Stilo

Brian Matthews, DeFINE, Pisa 26/11/02 CLRC in SWAD-Europe Three major areas –Developing XML Schemas from the Semantic Web –Developing tools and techniques for representing thesauri in the Semantic Web Especially Multilingual Thesauri –Developing tools and techniques for representing and processing Trust relationships in the Semantic Web.

Brian Matthews, DeFINE, Pisa 26/11/02 Trust Policies and Statements in RDF Express policy in RDF Present a trust statement to the Policy in RDF Proof satisfaction of one to other Problems: e.g. representing free variables. Edit_forms hasPolicy FRSPolicy Policy type positive subject Liz type Employee Project Manager jobtitle target type PolicyStatement /Finance/FrS Web/Lookup action Bag _1 load _2 display _3 fill _4 submit type

Brian Matthews, DeFINE, Pisa 26/11/02 Architecture Trust enabled web gateway resource Policy store TrustBase Trust reasoning engine Accessing agent Recommending agent RDF Statements

Brian Matthews, DeFINE, Pisa 26/11/02 Trust, Ontologies and Proof Use Web Ontologies work to: –Provide web accessible description of trust properties and policy frameworks –Add domain ontologies to customise to applications – role based trust management –Proof to demonstrate satisfaction of policy Initial Case study: –Frank Dale: Oxford Brookes Univ. MSc student –RDF formats for Access Control policies and –Added domain ontologies for role based access control. –Using XSLT to prove satisfaction of policies.

Brian Matthews, DeFINE, Pisa 26/11/02 What we want to do? Take a look at the existing methods related to trust on the Web –Those already in Semantic Web: PICS, P3P, CC/PP –Other Web trust initiatives: XSig, XEncrypt, XACML, SAML, Develop usage scenarios of trust on the Web Develop a Framework for Trust Modelling within the Semantic Web. –Ontologies for trust statements –Web based trust management –For trust policies Develop and implement a Web based architecture for trust usage. Develop tools for processing RDF statements against policies. Relate general trust values across all the applications –A general trust framework for the Semantic Web