Foundations of a CPS Resilience - October 2019

PI: Xenofon Koutsoukos

HARD PROBLEM(S) ADDRESSED

The goals of this project are to develop the principles and methods for designing and analyzing resilient CPS architectures that deliver required service in the face of compromised components. A fundamental challenge is to understand the basic tenets of CPS resilience and how they can be used in developing resilient architectures. The primary hard problem addressed is resilient architectures. In addition, the work addresses scalability and composability as well as metrics and evaluation. 

PUBLICATIONS

[1]    Aron Laszka, Xenofon Koutsoukos, and Yevgeniy Vorobeychik. Towards High-Resolution Multi-Stage Security Games. C. Wang and Z. Lu (eds.), Proactive and Dynamic Network Defense, Advances in Information Security 74, pp. 139-161. Springer, Cham, 2019.
[2]    Carlos Barreto and Xenofon Koutsoukos. "Attacks on Electricity Markets", 2019 57th Annual Allerton Conference on Communication, Control, and Computing (Allerton), September 24-27, 2019.
[3]    Amin Ghafouri, Aron Laszka, Waseem Abbas, Yevgeniy Vorobeychik, and Xenofon Koutsoukos. "A game-theoretic approach for selecting optimal time-dependent thresholds for anomaly detection," Autonomous Agents and Multi-Agent Systems, 33(4), 430-456, July 2019.
[4]    Waseem Abbas, Aron Laszka, and Xenofon Koutsoukos. "Diversity and Trust to Increase Structural Robustness in Networks", 2019 American Control Conference (ACC 2019), Philadelphia, PA, July 10-12, 2019.

KEY HIGHLIGHTS

This quarterly report presents two key highlights that demonstrate (1) increasing structural robustness in networks using diversity and trust and (2) integrated data space randomization and control reconfiguration for securing cyber-physical systems.

Highlight 1: Towards High-Resolution Multi-Stage Security Games

In recent years, we have seen a large number of cyber-incidents, which demonstrated how difficult it is to prevent cyber-breaches when facing determined and sophisticated attackers. In light of this, it is clear that defenders need to look beyond the first lines of defense and invest not only into prevention, but also into limiting the impact of cyber-breaches. Thus, an effective cyber-defense must combine proactive defense, which aims to block anticipated attacks, with reactive defense, which responds to and mitigates perceived attacks (e.g., isolating and shutting down compromised components).  
However, planning defensive actions in anticipation of and in response to strategic attacks is a challenging problem. Prior work has introduced a number of game-theoretic security models for planning defensive actions, such as Stackelberg security games, but these models do not address the overarching problem of proactive and reactive defenses in sufficient detail. To bridge this gap, we introduce a modeling approach for building high-resolution multi-stage security games. We describe several approaches for modeling proactive and reactive defenses, consider key modeling choices and challenges, and discuss finding optimal defense policies. With our study, we aim to lay conceptual foundations for developing realistic models of cyber-security that researchers and practitioners can use for effective cyber-defense.

[1]    Aron Laszka, Xenofon Koutsoukos, and Yevgeniy Vorobeychik. Towards High-Resolution Multi-Stage Security Games. C. Wang and Z. Lu (eds.), Proactive and Dynamic Network Defense, Advances in Information Security 74, pp. 139-161. Springer, Cham, 2019.

Highlight 2: 

In this work we analyze how an adversary (who participates in the electricity market) can manipulate the bids of other agents to change the market's equilibrium. Here the adversary attempts to profit without damaging the system. We formulate the adversary's goal as the solution of a biased efficiency metric and identify the precise attack that maximize the adversary's objective function. We propose a defense scheme that modifies the bids to mitigate the impact of the attack. We validate the results simulating a detailed electric distribution system equipped with a transactive energy market using GridLAB-D.

[2]    Carlos Barreto and Xenofon Koutsoukos. "Attacks on Electricity Markets", 2019 57th Annual Allerton Conference on Communication, Control, and Computing (Allerton), September 24-27, 2019.

COMMUNITY ENGAGEMENTS

Our research was presented in the American Control Conference 2019 and also in the 2019 57th Annual Allerton Conference on Communication, Control, and Computing (Allerton).