Real-time Attack-recovery for Cyber-physical Systems

What is it about?

In this paper, we study this attack response problem and propose novel real-time recovery for securing CPS. First, this work's core component is a recovery control calculator using a Linear-Quadratic Regulator (LQR) with timing and safety constraints. This component can smoothly steer back a physical system under control to a target state set before a safe deadline and maintain the system state in the set once it is driven to it. We further propose an Alternating Direction Method of Multipliers (ADMM) based algorithm that can fast solve the LQR-based recovery problem. Second, supporting components for the attack recovery computation include a checkpointer, a state reconstructor, and a deadline estimator. To realize these components respectively, we propose i) a sliding-window-based checkpointing protocol that governs sufficient trustworthy data, ii) a state reconstruction approach that uses the checkpointed data to estimate the current system state, and iii) a reachability-based approach to conservatively estimate a safe deadline. Finally, we implement our approach and demonstrate its effectiveness in dealing with totally 15 experimental scenarios which are designed based on 5 CPS simulators and 3 types of sensor attacks.

Featured Image

Photo by Colin Watts on Unsplash

Photo by Colin Watts on Unsplash

Why is it important?

Two fundamental elements for the operation of safe and resilient cyber-physical systems are attack detection and recovery. While the vast majority of existing works focus on attack detection, while little attention has been paid to attack recovery. In this paper, we study this problem and novel techniques on real-time recovery for securing CPS.