Hybrid Channel- and Coding-Based Challenge-Response Physical-Layer Authentication

TL;DR

This paper introduces a novel physical-layer authentication method combining channel state information and secret keys, utilizing wiretap coding and CSI verification to enhance security in systems with partial channel control.

Contribution

It presents a hybrid authentication scheme that leverages both CSI and secret keys, incorporating wiretap coding to conceal keys and improve security.

Findings

Trade-off analysis between pilot signals and coding rate.

Enhanced security through combined CSI and key verification.

Feasibility of using intelligent reflecting surfaces for authentication.

Abstract

This letter proposes a new physical layer authentication mechanism operating at the physical layer of a communication system where the receiver has partial control of the channel conditions (e.g., using an intelligent reflecting surface). We aim to exploit both instantaneous channel state information (CSI) and a secret shared key for authentication. This is achieved by both transmitting an identifying key by wiretap coding (to conceal the key from the attacker) and checking that the instantaneous CSI corresponds to the channel configuration randomly selected by the receiver. We investigate the trade-off between the pilot signals used for CSI estimation and the coding rate (or key length) to improve the overall security of the authentication procedure.