On Quantization for Secret Key Generation From Wireless Channel Samples

Muhammad Adil,Syed Junaid Nawaz,Shurjeel Wyne

doi:10.1109/access.2021.3055561

Abstract

Physical layer security (PLS) techniques hold promise for augmenting secure communications in the 5 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> generation of mobile wireless networks. Secret key generation (SKG) is a PLS technique which exploits the wireless propagation channel's randomness to generate symmetric key bits for information encryption and decryption. This work proposes symmetric key generation based on non-uniform quantization of the received signal strength (RSS) samples of a Nakagami-$m$ fading channel. The proposed strategy for non-uniform quantization for SKG aims to set quantization thresholds for maximal key randomness and high values of key generation rate (KGR) and key agreement probability (KAP). Finally, a framework is proposed to use single node RSS measurements, readily available in the literature, to generate RSS samples at the other link end. This framework facilitates the testing of new SKG algorithms that require simultaneous RSS measurements by the legitimate nodes, which are not readily available in the open literature. The effectiveness of the proposed SKG scheme is validated through Monte Carlo methods and the National Institute of Standards and Technology (NIST) test suite for assessing the randomness of the generated key sequence.

Highlights

The commercial deployment of the 5th generation (5G) of wireless networks has recently begun
The performance of SECRET KEY GENERATION (SKG) methods is conventionally measured by metrics such as key generation rate (KGR), i.e., number of key-bits generated per channel sample, bit miss-match probability (BMP), i.e., probability of mismatch between key-bits generated at the legitimate nodes, and randomness of the generated key sequence as quantified by the National Institute of Standards and Technology (NIST) test suite [31])
CONTRIBUTIONS AND ORGANIZATION The proposed work builds on prior received signal strength (RSS)-based SKG methods with consideration of the actual underlying probability density function (PDF) of the channel RSS samples in order to achieve a robust performance in terms of KGR, BMP, and key randomness properties

Summary

INTRODUCTION

The commercial deployment of the 5th generation (5G) of wireless networks has recently begun. Computational security methods implemented at higher layers of the protocol stack Such methods are based on publickey cryptography, wherein a public key is freely shared over the network to encrypt the information and a private key is retained only by the intended receiver to decrypt the encrypted message [2]. These traditional methods assume that the eavesdropping device has a limited computational ability and so it cannot decipher the secret information within reasonable time. Adil et al.: On Quantization for Secret Key Generation From Wireless Channel Samples

PHYSICAL LAYER SECURITY

SYSTEM MODEL

SIMULATION RESULTS

CONCLUSION