Radio Frequency Fingerprinting for Frequency Hopping Emitter Identification

Jusung Kang,Hyunku Lee,Younghak Shin,Heungno Lee,Jintae Park

doi:10.3390/app112210812

Abstract

In a frequency hopping spread spectrum (FHSS) network, the hopping pattern plays an important role in user authentication at the physical layer. However, recently, it has been possible to trace the hopping pattern through a blind estimation method for frequency hopping (FH) signals. If the hopping pattern can be reproduced, the attacker can imitate the FH signal and send the fake data to the FHSS system. To prevent this situation, a non-replicable authentication system that targets the physical layer of an FHSS network is required. In this study, a radio frequency fingerprinting-based emitter identification method targeting FH signals was proposed. A signal fingerprint (SF) was extracted and transformed into a spectrogram representing the time–frequency behavior of the SF. This spectrogram was trained on a deep inception network-based classifier, and an ensemble approach utilizing the multimodality of the SFs was applied. A detection algorithm was applied to the output vectors of the ensemble classifier for attacker detection. The results showed that the SF spectrogram can be effectively utilized to identify the emitter with 97% accuracy, and the output vectors of the classifier can be effectively utilized to detect the attacker with an area under the receiver operating characteristic curve of 0.99.

Highlights

Accepted: 11 November 2021The most important task in user authentication of a wireless communication system is to identify the emitter information of radio frequency (RF) signals
The novel receiver algorithm we propose in this study is an RF fingerprinting-based emitter identification (RFEI) method that targets the physical layer of the frequency hopping spread spectrum (FHSS) network
Spectrogram extracted from the received frequency hopping (FH) signal can be effectively analyzed using the utilized multimodality signal fingerprint (SF) was evaluated for robust classification

Summary

Introduction

Accepted: 11 November 2021The most important task in user authentication of a wireless communication system is to identify the emitter information of RF signals. A common way to confirm the emitter information, that is, the emitter ID, is to decode the address field of the medium access control (MAC) frame [1]. Under this digitized information-based authentication process on a MAC layer, an attacker can possess the address information and imitate it as an authenticated user. In the manufacturing of RF components inside an emitter, process tolerance is inevitable These tolerances affect subtle differences in the features of the emitted RF signal. Because these process tolerances are not reproducible, an SF can act as the fingerprint of an emitter. It can be utilized as a non-replicable authentication key to identify the authenticated user [3]

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Conclusion