Page 51 - Trust in ICT 2017
P. 51

Trust in ICT                                                1


            Establishing trust relationships between peers is an essential approach to prevent threats. For example, in
            Peer-to-Peer (P2P) systems, peers often interact with unknown or unfamiliar peers. P2P systems benefits
            highly  from  trust  mechanisms  for  a  peer  to  decide  whether  another  party  is  trustworthy  by  using  the
            knowledge of others.















































                             Figure 4 – Trust Establishment Contract Net Protocol Architecture [19]

            The high level view of Trust Establishment Protocol (TEP) is shown in the  Figure 4. The protocol mainly
            comprises of an Initiator Agent (IA), Bid Evaluation Agent (BEA), Contractor Agent (CA) and TEP, wherein TEP
            further comprises of Trust Verification Agent (TVA), Trust Matrix (TM in Figure 21) and Agent Registration
            List (ARL). The IA sends the list of keywords to be searched in the form of Call for Proposal (CFP) to the
            perspective CAs. CAs are not allowed to directly revert back to IA unless or until they possess Trust Certificate
            (TC). Therefore instead of reverting back to the respective IA, the CA executes TEP. Now, when a CA calls for
            authentication to TEP the TVA gets activated and in first instance it demands for certificate that authenticates
            the agents as registered agents. In turn CA presents all the certificates, it is possessed with. The TVA verifies
            the same and consults ARL if the same CA is a registered agent and had delivered the reliable results in past.
            If an entry for the same exists, the TM is consulted to compute trust percentile.
            6.2.5.1    Trust Establishment Policy

            To establish trust metrics and calculate trust score, there are a large number of properties that need to take
            into account. These properties could be trust-related attributes as well as ICT environment-related attributes.
            These policies for trust establishment vary from domain to domain, aspects to aspects. However, there are
            several categories for the policy which are in all ICT infrastructure domains.






                                                                                                           43
   46   47   48   49   50   51   52   53   54   55   56