Estimation of Output Channel Noise for Continuous Variable Quantum Key Distribution

TL;DR

This paper introduces a new method of moments estimator for channel noise in continuous variable quantum key distribution, significantly improving key rates especially in high loss scenarios.

Contribution

A novel estimator based on the method of moments that utilizes all shared states, reducing variance and increasing key rate in quantum communication.

Findings

Lower variance for high loss channels

Increases key rate by up to an order of magnitude

Effective use of all shared states

Abstract

Estimation of channel parameters is important for extending the range and increasing the key rate of continuous variable quantum key distribution protocols. We propose a new estimator for the channel noise parameter based on the method of moments. The method of moments finds an estimator from the moments of the output distribution of the protocol. This estimator has the advantage of being able to use all of the states shared between Alice and Bob. Other estimators are limited to a smaller publicly revealed subset of the states. The proposed estimator has a lower variance for high loss channel than what has previously been proposed. We show that the method of moments estimator increases the key rate by up to an order of magnitude at the maximum transmission of the protocol.