8. Recovery Planning

Despite the rapid development of cybersecurity, recovery of the operation of the impacted cyber-physical system (CPS) after a cyber-attack, as a core element of cyber resilience, is often left to human decision-makers. There is a high demand for an autonomous intelligent cyber defense agent (AICA) for planning a rapid recovery. In this chapter, we first show an overview of the state-of-the-art work in recovery planning. Then, we introduce and demonstrate a system for recovery planning using simulation-based predictive monitoring to recover the system from attacks (cyber, physical, or hardware) and disruptions automatically. The recovery planning system first evaluates the impact of system degradation and generates courses of actions (COAs) for recovery efficiently. Then, it evaluates these COAs through integrated heterogeneous simulations that account for unavoidable uncertainty. By formalizing security and safety requirements, it formally verifies recovery COAs with confidence guarantees, and obtains the optimal recovery COAs. We present two recovery scenarios in smart cities to demonstrate the effectiveness of our recovery planning system.