Designing Secure and Resilient Cyber-Physical Systems: a Model-based Moving Target Defense Approach

Cyber-physical systems (CPSs) rely upon the deep integration of computation and physical processes/systems, enabled by Internet of Things (IoT), edge computing, and cloud technologies. Noticeably, cybersecurity is a major concern in CPSs, since attacks may exploit both cyber and physical vulnerabilities and damage significantly physical equipment, compromise operational safety, and impact negatively on product quality and performance. In this context, CPS design should take both security and resilience requirements into account, by identifying the needed measures not only to prevent but also to withstand, recover from, and adapt to adverse conditions and attacks. The approach proposed in this paper aims at improving the security and resilience of a CPS deployment through a model-based design methodology leveraging security-by-design principles and Moving Target Defense (MTD) techniques, consisting in continually shifting a system configuration to reduce the attack success probability and survive attacks. Our methodology, in particular, is meant to support the threat modeling process of a CPS and the identification, based on spotted threats and on the properties of involved assets and data, of the security controls to include within the design to mitigate existing threats and of the MTD techniques to integrate in order to increase resilience.