Optimal Secure Control of Networked Control Systems Under False Data Injection Attacks: A Multi-Stage Attack-Defense Game Approach

Dear Editor, The attacker is always going to intrude covertly networked control systems (NCSs) by dynamically changing false data injection attacks (FDIAs) strategy, while the defender try their best to resist attacks by designing defense strategy on the basis of identifying attack strategy, maintaining stable operation of NCSs. To solve this attack-defense game problem, this letter investigates optimal secure control of NCSs under FDIAs. First, for the alterations of energy caused by false data, a novel attack-defense game model is constructed, which considers the changes of energy caused by the actions of the defender and attacker in the forward and feedback channels. Second, according to different participants (i.e., the attacker and defender) in different phases, the attack-defense game model contains four stages, and each stage is transformed into an optimization problem, where various attack strategies are operated by the attacker for different channels. Furthermore, at the Nash equilibrium, the defender can get optimal secure control strategy, which may resist attacks and greatly improve system security. Finally, the feasibility and effectiveness of the proposed method are confirmed, while system recovery ability is improved importantly.