Authentication of Satellite Navigation Signals by Wiretap Coding and Artificial Noise

TL;DR

This paper introduces a novel information-theoretic method for authenticating GNSS signals using wiretap coding and artificial noise, enhancing security against spoofing by making the authentication message undecodable to attackers while allowing legitimate verification.

Contribution

The paper proposes a new satellite signal authentication scheme combining orthogonal superimposed signals, artificial noise, and public decoding information, improving security against spoofing attacks.

Findings

The scheme achieves high secrecy capacity for authentication messages.

It effectively prevents attackers from decoding the secret message.

Performance analysis shows robustness under various attack scenarios.

Abstract

In order to combat the spoofing of global navigation satellite system (GNSS) signals we propose a novel approach for satellite signal authentication based on information-theoretic security. In particular we superimpose to the navigation signal an authentication signal containing a secret message corrupted by artificial noise (AN), still transmitted by the satellite. We impose the following properties: a) the authentication signal is synchronous with the navigation signal, b) the authentication signal is orthogonal to the navigation signal and c) the secret message is undecodable by the attacker due to the presence of the AN. The legitimate receiver synchronizes with the navigation signal and stores the samples of the authentication signal with the same synchronization. After the transmission of the authentication signal, through a separate public asynchronous authenticated channel (e.g., a secure Internet connection) additional information is made public allowing the receiver to a) decode the secret message, thus overcoming the effects of AN, and b) verify the secret message. We assess the performance of the proposed scheme by the analysis of both the secrecy capacity of the authentication message and the attack success probability, under various attack scenarios. A comparison with existing approaches shows the effectiveness of the proposed scheme.