Hierarchical Cyber-Attack Detection in Large-Scale Interconnected Systems

TL;DR

This paper introduces a hierarchical attack detection scheme for large interconnected systems, enabling early identification of local cyber-attacks with minimal data exchange, ensuring system stability and security.

Contribution

The paper proposes a novel hierarchical detection method that operates at the supervisory level, analyzing local attack signals with limited data exchange, enhancing security in large-scale systems.

Findings

Effective detection of local cyber-attacks demonstrated

Limited data exchange required for detection

Theoretical analysis confirms robustness and detectability

Abstract

In this paper we present a hierarchical scheme to detect cyber-attacks in a hierarchical control architecture for large-scale interconnected systems (LSS). We consider the LSS as a network of physically coupled subsystems, equipped with a two-layer controller: on the local level, decentralized controllers guarantee overall stability and reference tracking; on the supervisory level, a centralized coordinator sets references for the local regulators. We present a scheme to detect attacks that occur at the local level, with malicious agents capable of affecting the local control. The detection scheme is computed at the supervisory level, requiring only limited exchange of data and model knowledge. We offer detailed theoretical analysis of the proposed scheme, highlighting its detection properties in terms of robustness, detectability and stealthiness conditions.