Network Security for Cyber-Physical Systems: Towards Zero Trust

The Fourth Industrial Revolution has permanently bridged the digital and physical worlds, transforming traditionally isolated industrial control environments into highly interconnected cyber-physical systems (CPS). As operational technology, information technology, networks, sensors, controllers and physical processes become increasingly integrated, traditional network perimeters are no longer sufficient—and the attack surface expands accordingly.

Zero-Trust Architecture (ZTA), grounded in the principle of “never trust, always verify,” provides a fundamentally different security model. Continuous authentication and authorisation, least-privilege access, micro-segmentation and dynamic, context-aware security policies replace implicit trust with continuously evaluated trust decisions.

For cyber-physical systems, however, applying Zero Trust is not simply a matter of implementing stronger cybersecurity controls. Engineers must reconcile these mechanisms with resource-constrained devices, deterministic communications, real-time control, availability requirements and safety-critical operational constraints. Security decisions that are acceptable in conventional IT environments can have very different consequences when they interact directly with physical processes.

This presentation examines the evolving security architecture of modern cyber-physical infrastructure and explores the engineering tension between continuous security verification and real-time operational performance. It considers how Zero-Trust principles can be applied without compromising the responsiveness, availability and resilience upon which critical physical systems depend.

About Dr. Daniel Ramotsoela #

Daniel Ramotsoela received his B.Eng., M.Eng., and Ph.D. degrees in computer engineering from the University of Pretoria in 2013, 2015, and 2020, respectively. He is currently an Associate Professor in the Department of Electrical Engineering at the University of Cape Town (UCT) and is a founding member of the Intelligent Connectivity Research Group. He also serves as the chair of the Transformation Committee in the faculty of Engineering and the Built Environment (EBE) and the deputy chair of the Cyber-Security Chapter of the South African Institute of Electrical Engineers (SAIEE). He conducts research within the broad fields of cybersecurity, artificial intelligence and telecommunications, primarily focusing on IoT applications and cyber-physical systems. His current research focuses on zero-trust architecture in time-critical resource constrained networked infrastructure.