A physics‐based strategy for cyber resilience of CPS

Naval forces rely heavily on Cyber-Physical Systems (CPS) to conduct operations and achieve mission success. As CPS infrastructure becomes exposed to the contested world through networks, CPS security becomes much more important. In a CPS, the cyber components manage the physical components. ONR proposes that the overall goal for CPS resiliency is to have the physical systems behave properly regardless of fault and disruption. Our approach to CPS resiliency focuses on the physical components. We observed that the inertia of the physical components provides a natural but limited resilience, and is capable of tolerating short-term disruption without affecting the health and safety of the CPS. This and the fact that a CPS has a large difference between physical and cyber time scales, enables a unique approach to CPS resiliency. We present Byzantine Fault Tolerant++ (BFT++), a cyber resilient architecture that engineers the cyber components to be brittle against attack, which consequently forces cyber attacks and related disruptions to be short-lived and within tolerance of the physical system’s inertia.