A PUF-Based Security Framework for Fault and Intrusion Detection

Industrial Control Systems (ICS) rely on sensor feedback to keep safety-critical processes within operational limits. This research presents a hardware-root-of-trust that embeds a Physically Unclonable Function (PUF) at the measurement layer to authenticate sensor readings. The architecture combines voltage fingerprinting with a temporal authentication that integrates with standard industrial control system architecture. The research prototypes the PUF integration on a hardware-in-the-loop (HIL) water tank testbed using a Simulink-based PUF emulator. The system maintains 99.97% accuracy over a 5.18-hour period of normal operation and flags all injected anomalies, including spike faults, hard-over faults, and hardware trojan scenarios that push the system over to an unsafe operational state. The proposed architecture provides a process-aware, vendor-agnostic approach that can integrate with legacy plants to detect sensor signal degradation or sophisticated supply chain attacks.