Distributional Transform Based Information Reconciliation

TL;DR

This paper introduces a novel information reconciliation protocol for Continuous-Variable Quantum Key Distribution (CVQKD) using the Distributional Transform, achieving high efficiency even at low signal-to-noise ratios.

Contribution

It develops the Distributional Transform Expansion (DTE) method combining copula and information theory for improved CVQKD reconciliation.

Findings

Reconciliation efficiency exceeds 0.9 at -3.6 dB SNR for heterodyne measurements.

Derived maximum efficiency expressions for homodyne and heterodyne CVQKD protocols.

Method enhances key distribution robustness in noisy quantum channels.

Abstract

In this paper, we present an information reconciliation protocol designed for Continuous-Variable QKD using the Distributional Transform. By combining tools from copula and information theory, we present a method for extracting independent symmetric Bernoulli bits for Gaussian-modulated CVQKD protocols, which we called the Distributional Transform Expansion (DTE). We derived the expressions for the maximum reconciliation efficiency for both homodyne and heterodyne measurements, which, for the last, is achievable with an efficiency greater than 0.9 at a signal-to-noise ratio lower than -3.6 dB.