A sequential game model of defense and attack on interdependent systems

This research studies the defense strategy of an interdependent system in the face of rational attacks. We proposed a new model of sequential game between an attacker and a defender on an interdependent system of systems (SoS) to explore the effect of interdependency on the optimal defense strategy. An algorithm of backward induction is developed to determine the equilibrium path of the game. The attacker is the first mover as he applies an attack strategy on constituent systems that maximize his utility. The defender observes and responds by an optimal defense strategy which maximizes her utility. The utility is evaluated as the difference between a player’s reward and the cost of the action. The sensitivity analysis is carried out to compare the effects of different parameters on the attacker and defender’s strategies such as the effectiveness of defense, the effectiveness of attack, the unit cost of defense and the unit cost of attack on constituent systems