Page 75 - Trust in ICT 2017
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Trust in ICT                                                1


            expectations),  TrustProfile  (trust  guarantees),  TrustAttribute,  Measurable  TrustAttribute  and
            NonMeasurable TrustAttribute.













































                                               Figure 20 – Trust ontology [77]
            Semantic Matchers

            Discovery of the trustworthy products is a semantic matching or semantic search task. The trust expectations
            of a user are semantically matched with the trust guarantees of a service/product. The trust expectations
            and guarantees may match exactly, almost or be disjoint. If the trust guarantees match the trust expectations
            exactly or almost, the product classifies as trustworthy. If disjoint, the product classifies as distrusted. With
            the  trust  expectations  and  trust  guarantees  expressions  communalized  and  formalized  using  semantic
            vocabularies  and  machine-processable  semantic  annotations,  the  trust-based  discovery  engines  will  be
            capable to do better job, thanks to the semantics.
            There are many existing semantic matchers and semantic search engines available. The existing ones can be
            reused to develop a special-purpose engine for matching the trust expectations with trust guarantees. In
            particular [77] have developed a trust evaluation module on the top of a trust goal classification approach
            introduced  in  [78],  which  was  designed  for  the  trust-based  discovery  of  semantic  web  services.  In  that
            approach, trust guarantees of the web services are matched against trust expectations by a classification
            technique to identify services that fit (classify) into the requirement. In addition to the classification, they
            have introduced the measure of similarity between the trust expectations and trust guarantees. The measure
            is a value between 0 and 1, and represents the trust level.

            Importantly,  the  trust  guarantees  should  be  constantly  or  periodically  verified  and  monitored,  by  users
            and/or by established central authorities, in order to help to increase accuracy of the trust evaluation. The
            monitoring is collecting the evidence for the claimed trust guarantees. The monitoring of trust guarantees
            requires sophisticated mechanisms over the Internet with possible involvement of trusted third parties for
            detecting, isolating and limiting the negative behaviours. It is a challenge on its own.


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