Decentralized Stealth Attacks on Cyber-Physical Systems
Xiuzhen Ye, Inaki Esnaola, Samir M. Perlaza, Robert F. Harrison
TL;DR
The paper addresses the vulnerability of CPS to decentralized stealth data-injection attacks by formulating attacker actions as random Gaussian inputs that minimize the global mutual information $I(X^n;Y_A^m)$ while constraining the KL divergence $D(P_{Y_A^m}\|P_{Y^m})$. It introduces three normal-form potential games ${\cal G}_1,{\cal G}_2,{\cal G}_3$ with convex cost functions, proves the existence and uniqueness of Nash Equilibria, and provides best-response dynamics to reach them. The analysis includes both global and local information metrics, with explicit convexity proofs and closed-form best-response updates, along with numerical evaluations on IEEE test systems to demonstrate convergence and tradeoffs between disruption and detectability. The results show that decentralized game-theoretic attack constructions are feasible and predictable, enabling scalable analysis and highlighting practical risks to CPS security under limited attacker coordination. Overall, the work links information-theoretic disruption, stealth criteria, and game theory to characterize and achieve decentralized stealth attacks in CPS, offering insights for both attack design and defense planning.
Abstract
Decentralized stealth attack constructions that minimize the mutual information between the state variables and the measurements are proposed. The attack constructions are formulated as random Gaussian attacks targeting Cyber-physical systems that aims at minimizing the mutual information between the state variables and measurements while constraining the Kullback-Leibler divergence between the distribution of the measurements under attacks and the distribution of the measurements without attacks. The proposed information metrics adopted measure the disruption and attack detection both globally and locally. The decentralized attack constructions are formulated in a framework of normal games. The global and local information metrics yield games with global and local objectives in disruption and attack detection. We have proven the games are potential games and the convexity of the potential functions followed by the uniqueness and the achievability of the Nash Equilibrium, accordingly. We proposed a best response dynamics to achieve the Nash Equilibrium of the games. We numerically evaluate the performance of the proposed decentralized stealth random attacks on IEEE test systems and show it is feasible to exploit game theoretic techniques in decentralized attack constructions.
