Which Targets to Protect in Critical Infrastructures - A Game-Theoretic Solution From a Network Science Perspective

Modern society is highly dependent on its critical infrastructures. These infrastructures usually suffer intentional attacks, which is a serious threat to social wellbeing, making the protection of them to be a great challenge for the security agencies. Many game models have been proposed to tackle this problem. However, little of them consider the interrelationship of different targets within the infrastructures. In this paper, the protection of critical infrastructures against a malicious attacker is modeled as a simultaneous game, where the payoffs of the players are evaluated on the basis of the topology structure of the infrastructure system. An efficient algorithm is adopted to obtain the Nash equilibrium solution. The experimental results reveal that in the equilibriums, the defender distributes higher probabilities on protecting the targets who are more important, for example, those with large degrees or betweenness, while the attacker prefers attacking targets with medium degrees or betweenness. The effectiveness of the game-theoretic solution is validated, and the experimental results in a real-world network provide us a clear insight on which targets to protect.