Secure Two-Way Communications via Intelligent Reflecting Surfaces

TL;DR

This paper introduces a method using intelligent reflecting surfaces to enhance the security of multiuser two-way communications by employing signal jamming and user scheduling, with theoretical analysis and simulations confirming improved secrecy performance.

Contribution

It proposes a novel IRS-based scheme with user scheduling for secure two-way communication, including analytical bounds and scaling laws for secrecy rate.

Findings

Analytical lower bounds on average secrecy rate are derived.

The proposed scheme outperforms baseline schemes in simulations.

Secrecy performance scales favorably with system parameters.

Abstract

In this letter, we propose to exploit an intelligent reflecting surface (IRS) to secure multiuser two-way communications. Specifically, two end users simultaneously transmit their signals, where the signal of one user is exploited as information jamming to disrupt the reception of the other user's signal at an eavesdropper. A simple user scheduling scheme is developed to improve the secrecy rate. Analytical results in terms of a lower bound on the average secrecy rate and its scaling laws are derived to evaluate the secrecy performance and obtain valuable design insights. Simulation results are provided to confirm the accuracy of the theoretical analysis and validate the secrecy improvement of the proposed scheme over other baseline schemes.