Mitigation of Cyber-Physical Attacks in Industry 4.0 Using Secure Function Blocks

As Industry 4.0 drives the Fourth Industrial Revolution, Cyber-Physical Systems (CPSs) have become central to industrial automation. These systems integrate software with physical processes, significantly improving the efficiency and adaptability. However, this integration also expands the attack surface, exposing systems to Cyber-Physical-attacks (CP-attacks) that can target either the computational components, physical devices, or both. The impact of such attacks can be catastrophic, ranging from system disruption to physical damage. Although numerous techniques have been developed to detect and mitigate these threats, industrial standards are often not incorporated into the design of these methods. This limits their deployment within the Industry 4.0 systems, where standard compliance is critical. To this end, we extend IEC 61499, an emerging standard being considered in Industry 4.0, that uses reusable artefacts called function blocks. We formalise the mitigation of CP-attacks using a novel method based on Bi-directional Runtime Enforcement (Bi-RE) using a standards compliant approach called Secure Function Blocks (SFBs). This approach automatically generates the necessary enforcers from a timed specification language called Valued Discrete Timed Automaton (VDTA). We illustrate our approach using the case study of a water treatment system, and highlight the low overhead associated with it. This approach allows for runtime techniques to be applied with minimal changes to many Industry 4.0 applications.