Incentive Based Routing Protocols In Ad Hoc NetworksOverviewBasics…Ad Hoc NetworksMotivationDefinition: Incentive based SchemesEngineering Incentive based ProtocolsSlide 7AnalysisDesignEvaluationSome definitionsIncentive SchemesSORI A Secure Objective Reputation based Incentive schemeSlide 14AssumptionsBasic SchemeBasic Scheme continued …SORI: Basic Scheme continued …Basic Scheme: Summary & RemarksSecurity EnhancementsSlide 21Slide 22Simulation ResultsSlide 24PerformanceSPRITE Simple Cheat Proof Credit Based System for Mobile Ad hoc NetworksFeaturesBasic SchemeSlide 29Cheating actions in the submission gameMotivation nodes to forward the messageMotivation nodes to report ReceiptsPreventing false ReceiptsMessage Forwarding Protocol: SpecificationsSlide 35Slide 36Slide 37Slide 38Slide 39ConclusionReferencesIncentive Based Routing Protocols InAd Hoc NetworksVinay ShahCSE 620OverviewBasics…Ad Hoc NetworksMotivationDefinitionSteps for Engineering Incentive Schemes in a protocolIncentive based Routing ProtocolsReputation based: SORICredit Based: SPRITEBasics…Ad Hoc NetworksSet of nodes who wish to communicate without any network infrastructure.All nodes equipped with transmission and receiving capabilityNot every node is in the range of every other node.Thus the node has to take assistance of intermediate nodes if it want to transmit packets to other nodes not in its range of transmission.Usage: E.g. For communication during emergency and military situations (Cooperative ad hoc networks) or in general when nodes want to communicate in a civilian domain (Non-Cooperative ad hoc network)MotivationOverview: An ad hoc routing protocol The routing function is distributed among the participating nodes Current ad hoc routing protocols assumes that all the nodes are cooperativeHowever, forwarding of packets consumes resources such as battery power which are scarce. If the nodes in an non cooperative network belong to different users, they don’t have any incentive to cooperateThe routing component of any such protocol will not work if the nodes are selfish as the information provided by nodes may not be correctThus to prevent this, protocols should have an incentive scheme associated with them.Definition: Incentive based SchemesIn ad hoc networks, devices have to cooperate. Autonomous devices tend to abstain from cooperation. Incentive schemes have been proposed as a means of fostering cooperation under these circumstances Note: In order to work effectively, incentive schemes need to be carefully tailored to the characteristics of the cooperation protocol they should support.E.g. If Node A wants to Communicate with Node Z (Z not in its radio range). The intermediate nodes B, C … Y need some kind of incentive to use their resources to forward packets. BA C …………...ZEngineering Incentive based ProtocolsThe systematic design of incentive schemes comprises several steps.Analysis: The engineer analyzes and adjusts the cooperation protocol that requires an incentive scheme.Design: Design decisions have to be made regarding the choice of incentives, who should get the incentives and the means of implementing them.Evaluate: The resulting cooperation protocol is evaluated by applying an appropriate evaluation method.Analysis Questions that need to be answeredWhat kinds of inter-entity cooperation exist? Determined by the cooperation protocol the entities run. Which steps of the cooperation protocol are not beneficial to the executing entity? Is the behavior perceptible? If yes, how costly and reliable is such perception? Adjustments needed to make protocol more perceptible? There are several Perception mechanisms: Digital signatures: Check the authenticity of the sender and If entities of the forwarding path altered the packet. Redundancy: E.g. Extend the protocol to accommodate the issuance of receipts Over Hearing: Over hear to check if the entity is behaving as it shouldDesignDesign decisionsWhich type of behavior should be remunerated and which type should be taken as granted.How should a defecting entity be punished?Choice of appropriate incentives An incentive pattern induces that an entity enters into a otherwise detrimental commitmentIncentive patterns fall into two classes:Trust based: Entity may believe that its peers will reciprocate by entering into future commitments. Trade based: Entity is convinced to enter into a commitment if its peers enter into commitments that are beneficial for itself. Notes/Credits is a trade based approachIf exchange protocols are not viable, use distributed reputation systemsEvaluationSimulations provide the only cost-efficient means for such evaluationEvaluations focused on the total utility of the participating entitiesEvaluate the fairness of the incentive scheme with respect to the individual utility/costs that arise from cooperationHigh degrees of fairness indicate that entities have to exhibit cooperative behavior in order to benefit from the behavior of other entities.Cooperation protocol has to be modeled appropriately in order to obtain meaningful simulation results.Objectives of the evaluation: The engineer has to measure the total utility u and the total costs c that arise from cooperation. If the objectives of the evaluation include fairness, the individual utility ui and individual costs ci have to be measured separately for every entityA straightforward means of correlation is the calculation of a regression line between the individual utilities and costs.In case of good linear correlation, the slope of the regression line indicates the magnitude of the incentive effects.Some definitionsMalicious Entity: Aims at breaking the co operative paradigm to intentionally damage othersSelf-Interested Entity: Unwilling to spend its resources on behalf of others. Does not intend to damage the overall functioningIncentive SchemesReputation based schemeSORI: A Secure Objective Reputation based Incentive scheme Pricing/Credit Based SchemeSPRITE: Simple Cheat Proof Credit Based System for Mobile Ad hoc NetworksSome DefinitionsMalicious Entity: Aims at breaking the co operative paradigm to intentionally damage othersSelf-Interested Entity: Unwilling to spend its resources on behalf of others. Does not intend to damage the overall functioningSORIA Secure Objective
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