UC Santa Cruz

Cyber-Physical Systems (CPS) have traditionally been considered more static with more regular communication patterns when compared to classical information technology networks. Because the structure of most CPS remains unchanged during long periods of times, they become vulnerable to adversaries with the precise knowledge of the system, and who can tailor their attacks based on their knowledge about the system dynamics, communications, and control. Moving Target Defense (MTD) has emerged as a key strategy to add uncertainty about the state and execution of a system in order to prevent attackers from having predictable effects with their attacks. In the last few years MTD has been used in different CPS scenarios by adding uncertainties into the physical characteristics of the system. Most of these applications are used to detect attacks, or to make difficult for attackers to gather information. In this chapter, we propose an MTD strategy for multi-vehicle systems that can be used to mitigate the impact caused by cyber-attacks. We characterize the trade-off between impact mitigation and performance degradation, and illustrate the viability of our approach in two applications, (1) vehicular platooning, and (2) UAV formation. Finally, we extend our results to a more general control systems framework, and we introduce different types of MTD mechanisms, i.e., at the controller level and at sensors.