Industry 4.0, Cybersecurity, Current-state opacity, Discrete-Event systems, Finite state automata
Abstract
In this paper, the current-state opacity of networked discrete-event systems that transmit only vectors of changes in sensor and actuator signals to external agents is introduced. We show that the transmission of these vectors, called event vectors, generates in some cases, an uncertainty in the states reached by the system if the attacker does not know the system state when it is attacked, which can ensure the system current-state opacity. We also show that if the system is not opaque, then it is possible to select maximal sets of signals of the event vectors to be transmitted to the intended receiver ensuring current-state opacity.
