Nash Equilibrium Control Policy against Bus-off Attacks in CAN Networks

TL;DR

This paper models and analyzes a game-theoretic approach to designing optimal control policies against bus-off denial-of-service attacks in CAN networks, providing Nash equilibria and conditions for bounded costs.

Contribution

It introduces a stochastic transmission policy modeled as a game, deriving Nash equilibria and optimal control strategies under different attacker information scenarios.

Findings

Attacker has a dominant attack strategy in both information structures.

Optimal control policy is linear in the system state under the dominant attack.

Conditions for transmission policies to ensure bounded average cost are identified.

Abstract

A bus-off attack is a denial-of-service (DoS) attack which exploits error handling in the controller area network (CAN) to induce an honest node to disconnect itself from the CAN bus. This paper develops a stochastic transmission policy as a countermeasure for the controller-transmitter pair against the bus-off attack. We model this as a non-zero-sum linear-quadratic-Gaussian game between the controller-transmitter pair and the attacker. We derive Nash equilibria of the game for two different information structures of the attacker. We show that the attacker has a dominant attack strategy under both information structures. Under the dominant attack strategy, we show that the optimal control policy is linear in the system state. We further identify a necessary and a sufficient conditions on the transmission policy to have bounded average cost. The theoretical results are complemented by a detailed case study of a bus-off attack on a vehicular adaptive cruise control model.