A game-theoretic model on coalitional attacks in smart grid

The diverse cyber attacks, that make operation of the smart grid challenging, must be addressed before wide adoption of smart grids can be fully realized. Although a number of research efforts have been devoted to defending against these threats, a majority of existing schemes focus on the design of a specific defensive strategy to deal with a specific threat. In this paper we address the issue of coalitional attacks that can be launched by multiple adversaries cooperatively in the smart grid. We propose a game-theoretic based model to capture the interaction among multiple adversaries and quantify the capacity of the defender based on the extended Iterated Public Goods Game (IPGG) model. In the formalized game model, each participant can either cooperate by participating in the coalitional attack, or defect by standing aside in each round of the attack. We consider the generic defensive strategy that has a probability to detect the coalitional attack. When the coalitional attack is detected, all the participating adversaries are penalized. The expected payoff of each participant is derived through the zero-determinant strategy that provides the participants competitive benefits. Via a combination of theoretical analysis and experiments, our results show that our formalized game model can enable the defender to greatly reduce the maximum value of the expected average payoff to the adversaries via provisioning sufficient defensive resources, which is reflected by setting a proper penalty factor against the adversaries.