Moving Target Defense Strategy in Critical Embedded Systems: A Game-theoretic Approach

Moving Target Defense (MTD) is a promising de-fense technique that aims to break the asymmetry between attacker and defender by reconfiguring a system's assets. When used in a critical embedded system, non-functional constraints limit the set of usable MTD techniques, therefore limiting the entropy of reconfigurations. It is therefore necessary to compute an optimal moving target strategy in order to reduce the time between reconfigurations, while managing their impact on the quality of service provided to users. In this paper, we propose a game-theoretic approach to define an optimal moving target defense strategy. Our approach translates risk analysis parame-ters into a Bayesian Stackelberg game, which we translate to a mixed integer linear program. We validate our approach on an industrial case study from the automotive domain, showing the practical usability of our approach. In further experiments, we assess the scalability of our method, as well as the solution's stability in case new vulnerabilities are discovered after the deployment of the system.