Cost-Benefit Analysis of Moving-Target Defense in Power Grids

TL;DR

This paper analyzes the use of moving-target defense in power grids, proposing a formal design for effective reactance perturbations that balance attack detection with operational costs, validated through extensive simulations.

Contribution

It introduces a formal design criterion for effective MTD reactance perturbations and characterizes the tradeoff between detection effectiveness and operational cost.

Findings

Effective MTD can be designed with formal criteria.

Tradeoffs exist between detection capability and operational cost.

Simulations confirm the proposed approach's effectiveness.

Abstract

We study moving-target defense (MTD) that actively perturbs transmission line reactances to thwart stealthy false data injection (FDI) attacks against state estimation in a power grid. Prior work on this topic has proposed MTD based on randomly selected reactance perturbations, but these perturbations cannot guarantee effective attack detection. To address the issue, we present formal design criteria to select MTD reactance perturbations that are truly effective. However, based on a key optimal power flow (OPF) formulation, we find that the effective MTD may incur a non-trivial operational cost that has not hitherto received attention. Accordingly, we characterize important tradeoffs between the MTD's detection capability and its associated required cost. Extensive simulations, using the MATPOWER simulator and benchmark IEEE bus systems, verify and illustrate the proposed design approach that for the first time addresses both key aspects of cost and effectiveness of the MTD.