Cyber Physical Systems Security: Bridging Privacy, Verification, Intelligence, and Forensics

Cyber Physical Systems (CPS) now underpin critical sectors including energy, healthcare, transportation, and industrial automation, yet their tight coupling of computational intelligence with physical processes exposes them to sophisticated, multi-layer attacks. This survey provides a unified, end-to-end examination of CPS security by consolidating advances in privacy-preserving computation, hardware-rooted trust, intelligent intrusion detection, formal assurance, and digital forensics. To the best of our knowledge, this is the first survey to holistically interconnect these pillars within a comprehensive CPS security framework. The review introduces a structured taxonomy linking CPS security attributes to system assets, attack vectors, and defence strategies, and surveys publicly available CPS datasets, benchmarking environments, and experimental testbeds that support reproducible evaluation. It traces the evolution of differential privacy for data protection, physically unclonable functions for device identity, blockchain for integrity and provenance, AI/ML for adaptive threat detection, and formal verification for correctness and safety, while highlighting the emerging role of forensic readiness. Despite notable progress, CPS security faces persistent challenges in scalability, adversarial robustness, real-time deployment, interoperability, and benchmarking. To address these gaps, the article outlines a research roadmap emphasizing hybrid defence architectures, standardized datasets and testbeds, benchmarking standards, and adaptive governance models for resilient CPS ecosystems.