In this paper, Teixeira et al. address cybersecurity issues for networked control systems. Such systems are of great importance to our modern technology infrastructure and affect safety, health, and essential utilities. A model is defined, analyzed, and illustrated on an experimental basis. An attack space is envisioned with orthogonal dimensions of system knowledge, disclosure resources, and disruption resources, and the attack scenarios of replay, zero dynamics, and bias injection lend themselves to analysis in this space. The experimental environment is a quadruple-tank process that is wirelessly controlled. This setup is used to illustrate scenarios, consequences, and possible countermeasures.

The introductory section provides the motivation and a summary of related work, and introduces the attack space construct and an overview of the paper’s goals. The second section describes the structure of a networked control system, including the physical plan, the communication network, feedback control, and the detection of operation anomalies. The third section addresses the model of adversaries, discussing an attack on networked control systems in general, the role of system knowledge, disclosure resources that gather intelligence, and disruption resources, including physical, deception, and denial-of-service (DoS) attacks. The next section describes attack scenarios with goals and constraints, replay, zero dynamics, and bias injection. The last major section (5) presents the testbed for experimentation and the results for replay, zero dynamics, and bias injection attacks.

The paper is insightful and provides mathematics models and a number of helpful diagrams to present conceptual models and experimental results.