Stealthy sensor injection attacks are serious threats for industrial plants as they can
compromise the plant's integrity without being detected by traditional fault detectors. In this
manuscript, we study the possibility of revealing the presence of such attacks by monitoring
only the control input. This approach consists in computing an ellipsoidal bound of the input
reachable set. When the control input does not belong to this set, this means that a stealthy
sensor injection attack is driving the plant to critical states. The problem of finding this …