Undetectable Finite-Time Covert Attack on Constrained Cyber-Physical Systems

In the last few decades, several cyber-threats against cyber-physical systems (CPSs) have been reported. Of particular interest are the classes of network attacks capable of affecting the control systems' performance while remaining undetectable. In this article, under some conditions, we show the existence of a novel class of finite-time undetectable attacks against constrained CPSs. The proposed finite-time attack has the peculiar capability of not producing anomalies after its termination. This is particularly dangerous because it enables a malicious entity to repeatedly or intermittently affect the CPS without raising alarms. Such an attack is here designed by resorting to a set-theoretic approach that leverages robust reachability arguments. Moreover, given the desired attack duration, the set of initial states from which the attack is feasible is characterized. A numerical simulation example involving an industrial continuous-stirred tank reactor system is presented to support the theoretical results.