Subsystem-importance-aware DoS attacks and countermeasures

This paper is concerned with the security issue of remote state estimation in multi-systems. Note that different subsystems or local state information possess varying levels of importance. A novel denial-of-service (DoS) attack type, referred to as a subsystem-importance-aware DoS attack, is proposed. The importance of a subsystem refers to the quantitative impact of its information on the correctness or accuracy of decision-making for the entire system. Here, the importance of a subsystem is positively correlated with the power allocated to transmit local information. Additionally, it is assumed that the attacker has access to the transmission power of all subsystems. The optimal attack strategies are then investigated under different subsystem-importance weight functions and the error functions that are related to the packet arrival rate, and the closed-form solutions under some special cases are provided. Furthermore, potential defense strategies are investigated, leveraging the gap in the interpretation of the subsystem importance between the attacker and the defender, formulated as a Stackelberg game. Finally, numerical examples are provided to illustrate the theoretical results and provide insights into possible countermeasures against our proposed attack.