Trustworthy Sensor Networks

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Trustworthy Sensor Networks. Daniel Aegerter, 41542053 Supervisor: Rajan Shankaran. Agenda. Problem Statement Wireless Sensor Networks Notion of Trust in Wireless Sensor Networks Comparative Analysis Recommendations. Problem. - PowerPoint PPT Presentation

Text of Trustworthy Sensor Networks

  • AgendaProblem StatementWireless Sensor NetworksNotion of Trust in Wireless Sensor NetworksComparative AnalysisRecommendations*

  • ProblemSecurity is critical in many applications of Wireless Sensor Networks (WSNs)Battlefield surveillancePatient monitoringEnvironment monitoringSecurity mechanisms assume trustworthiness of participating nodesWhat happens if nodes get compromised?Access key materialChange content of messagesDrop messages Lives and livelihoods might depend on the correctness of the data


  • Wireless Sensor Networks (WSNs)Sensor nodes sense data from the environment and detect specific events Sensor nodes are equipped with sensors to monitor a wide range of physical conditions:Temperature, Humidity, Light, Pressure, Object motion, Noise, etc.Sensor nodes are constrained by limited resources

    *MemoryProcessor UnitCommunication devicePower Unit Sensor Unit

  • Network ArchitectureComponents of Wireless Sensor Networks Common Sensor NodesBase StationMultihop communication


  • Notion of TrustTrust is the subjective probability by which an individual, A, expects that another individual, B, performs a given action on which its welfare depends (Gambetta, 1988)*In the context of WSNsTrustworthy sensor nodes dont:Manipulate gathered informationAlter information received from neighbouring nodesFlood the network with bogus routing informationDrop messages received from other nodes

  • Challenges in Evaluating Trust for WSNsLimited processing, storage, and energy resourcesExisting protocols and mechanisms are not applicableMinimise communication overheadTrusted authority not present in WSNsPublic key mechanisms and certificates not suitableAdoption of architectural network changesDynamic nature of WSNsNodes may become faulty or compromised Trust re-evaluation is essential


  • Concept of Reputation-Based Trust SystemsTrust is based on a nodes behaviourDoes the node behave in a correct manner?Network events and correctness of gathered informationTrust evaluation through first and second-hand informationDirect observationsRecommendations from peersBuilding blocksWatchdog mechanism collects evidenceReputation system evaluates and maintains trust


  • Comparative AnalysisCompares five reviewed reputation-based frameworksReputation-based framework for high integrity sensor network (RFSN) Gaussian trust model and reputation system (GRSSN) Lightweight group based trust management scheme (GTMS)Trust-based cluster head electionCertificate and behaviour-based approach Determines characteristics and constraints of each frameworkProposes categories to conduct the comparative analysisTrust managementNode and network requirementTrust evaluation


  • Comparative Analysis Some CriteriaEvidenceNetwork events vs. correctness of sensed dataPre-established trust relationshipsDo sensor nodes trust each other at time of deployment?Storage complexityTables, keys, certificatesRevocationWhat happens with non-cooperative sensor nodes?


  • Comparative Analysis OutcomesAll frameworks have some design problemsDifficult to take all characteristics and constraints of WSNs into accountFrameworks are application specificDifferent assumptionsDifferent requirements (e.g. supernodes, keys, certificates)Sophisticated frameworks are more complexEconomical issuesManagement issuesEvidence analysisNetwork events or also correctness of sensed data?*

  • RecommendationsCollaborative reputation-based approach for establishing trustBehaviour of nodes is observed by a subset of sensor nodesOther nodes do not have to monitor network eventsGuardian nodesGuardian nodes evaluate collaborative trustworthiness of nodesAll sensor nodes are directly observable by guardian nodesGuardian node evaluate whether a node is cooperativeOpinions are shared among guardian nodesBlacklist entry has to be confirmed by other guardiansSensor node keep list with non-cooperative nodes


  • Recommendations - Example*

  • Future Research DirectionsAnalyse correctness of sensed data not only network eventsTrust evaluation for different roles that sensor node can performForward messagesAggregate dataSense information

    *Thank you

  • Questions*