Foundations of a CPS Resilience - April 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]    Akos Ledeczi, Miklos Maroti, Hamid Zare, Bernard Yett, Nicole Hutchins, Brian Broll, Peter Vogyesi, Michael B. Smith, Timothy Darrah, Mary Metelko, Xenofon Koutsoukos and Gautam Biswas. "Teaching Cybersecurity with Networked Robots". SIGCSE 2019. Minneapolis, MN, Feb. 27 - March 2, 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: Diversity and Trust to Increase Structural Robustness in Networks

In a networked system, any change in the underlying network structure, such as node and link removals due to an attack, could severely affect the overall system behavior. Typically, by adding more links and connections between nodes, networks can be made structurally robust. However, this approach is not always feasible, especially in sparse networks. In our work, we aim to improve the structural robustness in networks using the notions of diversity and trustiness. Diversity means that nodes in a network are of different types and have many variants. Trustiness means that a small subset of nodes is immune to failures and attacks. We show that by combining diversity and trustiness within the network, we can significantly limit the attacker’s ability to change the underlying network structure by strategically removing nodes. Using pairwise connectivity as a measure, we show that by appropriately distributing trusted nodes and assigning types to nodes, network robustness can be significantly improved. We analyze the complexity of diversifying and computing a set of trusted nodes, and then present heuristics to compute attacks consisting of node removals. We also present heuristics to defend networks against such attacks by distributing node types and trusted nodes. Finally, we evaluate our results on various networks to demonstrate the usefulness of our approach. Our results are presented in [1].

[1] Waseem Abbas, Aron Laszka, and Xenofon Koutsoukos. "Diversity and Trust to Increase Structural Robustness in Networks", 2019 American Control Conference. Philadelphia, PA. July 10-12, 2019.

Highlight 2: Integrated Data Space Randomization and Control Reconfiguration for Securing Cyber-Physical Systems

Non-control data attacks have become widely popular for circumventing authentication mechanisms in websites, servers, and personal computers. Moreover, in the context of Cyber-Physical Systems (CPS) attacks can be executed against not only authentication but also safety. With the tightly coupled nature between the cyber components and physical dynamics, any unauthorized change to safety-critical variables may cause damage or even catastrophic consequences. Moving target defense (MTD) techniques such as data space randomization (DSR) can be effective for protecting against various types of memory corruption attacks including non-control data attacks. However, in terms of CPS it is also critical to ensure the timely Cyber-Physical interactions after attacks thwarted by MTD. This work addresses the problem of maintaining system stability and security properties of a CPS in the face of non-control data attacks by developing a DSR approach for randomizing binaries at runtime, creating a variable redundancy-based detection algorithm for identifying variable integrity violations, and integrating a control reconfiguration architecture for maintaining safe and reliable operation. Our security framework is demonstrated utilizing an autonomous vehicle case study. Our results are reported in [2].

[2]  Bradley Potteiger, Zhenkai Zhang, and Xenofon Koutsoukos."Integrated Data Space Randomization and Control Reconfiguration for Securing Cyber-Physical Systems", Symposium and Bootcamp on the Science of Security, HotSoS 2019, Nashville, TN, April 2-3, 2019.

COMMUNITY ENGAGEMENTS

Our research was presented in the SIGCSE 2019 conference.

EDUCATIONAL ADVANCES

RoboScape

We continue developing and extending Roboscape, a collaborative, networked robotics environment that makes key ideas in computer science accessible to groups of learners in informal learning spaces and K12 classrooms. RoboScape will be used for summer camps for high-school students and teachers in 2019.