Trust management system design for the Internet of Things A….pptVIP

* * * * * * * * * * * * * Simple Concept Decrease QR score if witness gave a bad score to a good node Increase QR score if witness gave a good score to a good node Use weighted average avoids excessive variations of QR allows precise choice of extent to which QR must be oriented towards 1 (good recommender), 0 (non-usable data), and -1 (bad recommender) LEARNING 1: UPDATE QUALITY OF RECOMMENDATION LEARNING 1: QR DIRECTION Let X be a witness node who evaluated node P, which later provided a service to node F Node F sends report RF with score N {-1,0,1} TM uses Fs report to update QR score of each recommender System retrieves n stored QR scores for all witness nodes X has for example QRx (QR1,...,QRn-1, Qrn) System extracts note N from RF and retrieves wRx corresponding to RX QRXF represents direction that QR for X should evolve r = 1 if X and F agree on rating, r=-1 when they are opposite, and r=0 when they are off by 1 CF is weight of r, increases when weight of Xs previous report is high, increases if F is a good recommender LEARNING 1: WEIGHTED AVERAGE QRi represents Xs rec. history Ci is respective weight for Xs rec. history θ represents memory factor of system Negative N_QR means X is reporting opposite of actual service quality Instead of discarding Xs ratings, consider the opposite! Reputation distinct from trust Trust measures ability of node to perform specific task Reputation refers to overall trustworthiness of node in the system Combine QR (QRFj)and service ratings (NFj) with age-based weighting factor TM recalculates reputation after each interaction Nodes with low-reputation are added to blacklist LEARNING 2: UPDATE ASSISTING NODES REPUTATION LEVELS TEST SIMULATION SIMULATION PARAMETERS QR EVOLUTION QR EVOLUTION CONT. ATTACK RESILIENCE ATTACK RESILIENCE CONT. Presented generic, context-aware TMS for IoT Dynamic trust scores assigned to nodes based on node status, and required function Independent score given for Quality of Recommendation QR score is ad