A Distributed Trust Management Scheme for Data Forwarding in Satellite DTN Emergency Communications

摘要

Satellite Communications can be used whenudother communication systems are either destroyed or overloaded.udObservation satellites and Delay/Disruption TolerantudNetworks are technologies that can be interconnectedudto provide emergency communication for disaster recoveryudoperations. DTNs use a store-carry-forward mechanismudto forward messages through intermediary nodes to theuddestination node. The reliability of relaying messagesudthrough multi-hop nodes poses a significant problem inudDTNs due to lack of consistent connectivity. These networkudcharacteristics make DTNs to heavily rely on the cooperationudof neighbouring nodes for the successful delivery ofudpackets. However, the presence of malicious or selfish nodesudwill have a great impact on the network performance. Inudthis paper, we design a decentralised trust managementudscheme (DTMS) to filter out malicious nodes in DTNs.udFirst, the number of forwarding evidence are combinedudwith the energy consumption rate of the nodes to formulateuddirect trust. Then, a recommendation trust is computedudfrom the indirect trust, recommendation credibility andudrecommendation familiarity. Recommendation credibilityudand familiarity improve the overall recommendation trustudby filtering out dishonest recommendations. A comparativeudanalysis of DTMS is performed against a CooperativeudWatchdog Scheme (CWS), Recommendation Based TrustudModel (RBTM) and Spray & Wait protocol. The resultsudshow that DTMS can effectively deal with maliciousudbehaviours in DTNs including trust related attacks.