Secret-key generation from wireless channels: Mind the reflections

TL;DR

This paper introduces a new wireless channel model that accounts for antenna reflections, revealing their negative impact on secret-key rates at high SNR and offering design insights for secure communication systems.

Contribution

It proposes a novel channel model incorporating antenna reflections, enhancing understanding of their effect on secret-key generation in wireless environments.

Findings

Reflections reduce secret-key rate at high SNR

New model captures practical antenna effects

Guidelines for secure system design

Abstract

Secret-key generation in a wireless environment exploiting the randomness and reciprocity of the channel gains is considered. A new channel model is proposed which takes into account the effect of reflections (or re-radiations) from receive antenna elements, thus capturing an physical property of practical antennas. It turns out that the reflections have a deteriorating effect on the achievable secret-key rate between the legitimate nodes at high signal-to-noise-power-ratio (SNR). The insights provide guidelines in the design and operation of communication systems using the properties of the wireless channel to prevent eavesdropping.