Existence and construction of zero-determinant strategy for moving target defense

The moving target defense (MTD) is a defense paradigm in repeated security games within the realm of cybersecurity. The defender’s strong Stackelberg equilibrium (SSE) strategy is optimal for deployment as an MTD strategy, assuming that the attacker adopts a best-response strategy after observing the defender’s actions. However, computing SSE strategies in repeated games is complex due to the non-convexity of players’ expected utilities, especially when dealing with multiple targets in large-scale problems. Thus, we propose to use the zero-determinant (ZD) strategy as an MTD strategy to reduce computational complexity. To this end, we identify the conditions for the existence of the ZD strategy. Also, we provide a novel approach to construct the required ZD strategy.