High Bit Rate Continuous-Variable Quantum Key Distribution

TL;DR

This paper demonstrates a practical continuous-variable quantum key distribution protocol that achieves higher secret key rates than standard qubit-based protocols, including extracting over one bit per channel use.

Contribution

It introduces a novel postprocessing method enabling extraction of more than one secret bit per channel use in CVQKD, surpassing previous DV QKD capabilities.

Findings

Achieved secret key rates exceeding those of standard DV QKD

First practical implementation of postprocessing for >1 bit per channel use

Demonstrated feasibility of high-rate CVQKD in real-world settings

Abstract

Here, we demonstrate that a practical Continuous Variables Quantum Key Distribution (CVQKD) protocol relying on the Gaussian modulation of coherent states features secret key rates that cannot be achieved with standard qubit Discrete Variables (DV) QKD protocols. Notably, we report for the first time a practical postprocessing that allows to extract more than one bit of secret key per channel use.