Mitigation and Resiliency of Multi-Agent Systems Subject to Malicious Cyber Attacks on Communication Links

TL;DR

This paper investigates a novel cyber attack on multi-agent systems via communication links, analyzing conditions for control takeover, proposing security metrics, and demonstrating attack effectiveness through numerical examples.

Contribution

It introduces controllability attack concepts, security controllability indices, and explores zero dynamics cyber attacks in multi-agent systems.

Findings

Conditions for full network control by attackers

Development of security controllability indices

Effectiveness demonstrated through numerical example

Abstract

This paper aims at investigating a novel type of cyber attack that is injected to multi-agent systems (MAS) having an underlying directed graph. The cyber attack, which is designated as the controllability attack, is injected by the malicious adversary into the communication links among the agents. The adversary, leveraging the compromised communication links disguises the cyber attack signals and attempts to take control over the entire network of MAS. The adversary aims at achieving this by directly attacking only a subset of the multi-agents. Conditions under which the malicious hacker has control over the entire MAS network are provided. Two notions of security controllability indices are proposed and developed. These notions are utilized as metrics to evaluate the controllability that each agent provides to the adversary for executing the malicious cyber attack. Furthermore, the possibility of introducing zero dynamics cyber attacks on the MAS through compromising the communication links is also investigated. Finally, an illustrative numerical example is provided to demonstrate the effectiveness of our proposed methods.