Enhancing Cybersecurity for Industrial Control Systems: Innovations in Protecting PLC-Dependent Industrial Infrastructures

A robust approach for cybersecurity of industrial control systems (ICSs) that utilize programmable logic controllers (PLCs) to control critical industrial processes is demonstrated in this article. For example, the industrial water/chemical tank-based system, the liquid level sensor measurement output data may be compromised or manipulated by attackers, this can cause tank overflow, unregulated, or even malfunction. We proposed a general-purpose method called dynamic watermarking (DW) to secure ICSs. The basic idea of DW is that it adds a private random signal watermark on the control signal from the controller, then this watermark signal propagates through the plant and adequately converted then comes back to the attack detector. The attack detector at the actuator side can detect man-in-the-middle (MiTM) or masquerade attack on the cascading system in real time. The proposed method is experimentally tested and validated with the several cyber-attack scenarios on a laboratory scale water tank level control system controlled by an Allen-Bradley Micro820 PLC.