From Control System Security Indices to Attack Identifiability

TL;DR

This paper extends security indices to linear dynamical systems, quantifying resources needed for undetectable attacks, and applies fault detection techniques for attack identification amid disturbances.

Contribution

It generalizes security indices from static to dynamic systems and introduces methods for attack detection and identification considering disturbances.

Findings

Generalized security index for linear systems

Quantified resources for undetectable attacks

Applied fault detection techniques for attack identification

Abstract

In this paper, we investigate detectability and identifiability of attacks on linear dynamical systems that are subjected to external disturbances. We generalize a concept for a security index, which was previously introduced for static systems. The generalized index exactly quantifies the resources necessary for targeted attacks to be undetectable and unidentifiable in the presence of disturbances. This information is useful for both risk assessment and for the design of anomaly detectors. Finally, we show how techniques from the fault detection literature can be used to decouple disturbances and to identify attacks, under certain sparsity constraints.