Game Theoretical Dynamic Cybersecurity Defense Strategy for Electrical Cyber Physical Systems

The critical industrial infrastructures are facing increasing cyberspace threats and attacks in most recent years, the cyberspace security of different forms of Cyber Physical Systems (CPSs) has received much attention. The game theory is considered as an appropriate paradigm for formulating the behaviors of cyberspace attack and defense. This paper proposes a game theory based dynamic cybersecurity defense strategy in the context of electrical CPSs that relies on zero-sum game of incomplete information to identify the expected utility of attacker and defender under Nash equilibrium. The key idea of the proposed solution is to import physical security target and cyber safety index, analyze the asset value of different nodes in a multi-dimensional manner, and update Markov belief dynamically at each stage to reflect the understanding degree of both sides. The proposed solution is assessed through simulation experiments and the CPS testbed at Zhejiang University. The numerical results confirmed that the proposed method can carry out appropriate strategy for defense resources allocation in electrical CPS with the limited availability of defense resources.