Data-Driven Approximation of Formal Implicit Interaction Analysis for Cyber-Physical System Designs

Implicit interactions are a type of system vulnerability which refer to sequences of communication between components in a system that are unplanned, unexpected, and/or unforeseen by system designers. The presence of implicit interactions can have impacts on system safety, security, stability, and resilience. The existing work to identify and analyze implicit interactions, as well as locate areas in a system for redesign to mitigate implicit interactions, all require the use of formal methods, which limits industry adoption. In this work, we identify measurements based on graph abstractions of system design models that can be used to produce similar results as the aforementioned formal analyses. We demonstrate this on a model of a real-world wastewater dechlorination system. By combining data collected from formal and graph measurements, we provide alternate methods to evaluate the prevalence of implicit interactions within a system design that can make security-by-design more accessible and widely adopted for more secure and resilient cyber-physical systems.