High-dimensional autocompensating discrete modulation CV-QKD protocol in optical fibers

TL;DR

This paper introduces a high-dimensional discrete modulation CV-QKD protocol in optical fibers that uses autocompensation and demonstrates increased secure key rates with higher dimensions.

Contribution

It presents a novel high-dimensional CV-QKD protocol with autocompensation in optical fibers, enhancing security and key rates over existing methods.

Findings

Secure key gains increase with dimension N.

Passive autocompensation effectively cancels perturbations.

Protocol is analyzed against intercept-resend attacks.

Abstract

In this work we present a high-dimensional discrete modulated CV-QKD protocol, with dimension 2N , in optical fibers, where N is the number of optical modes. We use N-dimensional product states of weak coherent states that undergo perturbations along optical fibers and that are cancelled in a passive way (autocompensation) and then measured by a standard balanced homodyne detection. We analyze the security of this high-dimensional protocol when an intercept and resend attack is implemented with simultaneous homodyne measurement in both quadratures and the resulting secure key gains are calculated showing a significative increase with dimension.