Publications Repository - Gdańsk University of Technology

In client-server information systems with quality of service (QoS) differentiation, Client may deplete Server’s resources by demanding unduly high QoS level. Such QoS abuse has eluded systematic treatment; known defenses using Client authorization, payments, or service request inspection prior to QoS assignment, are heuristic and environment-specific. We offer a game-theoretic approach on the premise that a service request is occasionally trusted to reduce the inspection cost. We call Fake VIP attack (FVA) a form of QoS abuse that consciously exploits Server’s trust. An FVA strategy instills trust to maximize Client’s utility gained from successful FVAs, whereas a trust strategy maximizes Server’s utility by trading her loss due to successful FVAs against the request inspection cost. We consider a realistic scant-transparency setting where only long-term utilities are observable. Against a probabilistic FVA strategy we design a trust strategy based on double-blind reputation. Assuming a memoryless service request stream we analyze the impact of the request inspection cost and information leakage on the utilities at the Stackelberg equilibrium of the arising game. Experimental comparison with a real-world internally correlated stream is also shown.

Authors

• dr hab. inż. Jerzy Konorski link open in new tab