Secret Key Generation for Intelligent Reflecting Surface Assisted Wireless Communication Networks

TL;DR

This paper introduces a method for secret key generation in IRS-assisted wireless networks, optimizing IRS configurations to enhance security against eavesdroppers, with proven improvements in key capacity through simulations.

Contribution

It formulates the secret key capacity for IRS-assisted channels and develops an optimization algorithm to maximize this capacity, which is a novel approach.

Findings

Significant increase in secret key capacity with IRS optimization

Effective algorithm based on SDR and SCA methods

Robust performance across various wireless channel conditions

Abstract

We propose and analyze secret key generation using intelligent reflecting surface (IRS) assisted wireless communication networks. To this end, we first formulate the minimum achievable secret key capacity for an IRS acting as a passive beamformer in the presence of multiple eavesdroppers. Next, we develop an optimization framework for the IRS reflecting coefficients based on the secret key capacity lower bound. To derive a tractable and efficient solution, we design and analyze a semidefinite relaxation (SDR) and successive convex approximation (SCA) based algorithm for the proposed optimization. Simulation results show that employing our IRS-based algorithm can significantly improve the secret key generation capacity for a wide-range of wireless channel parameters.