Continuous-variable quantum key distribution with Gaussian source noise

TL;DR

This paper introduces a model for analyzing the security of continuous-variable quantum key distribution in the presence of Gaussian source noise by incorporating an auxiliary party, Fred, and derives tight security bounds for reverse reconciliation.

Contribution

The paper presents a novel model using an auxiliary party to characterize Gaussian source noise and derives tight security bounds for CV QKD.

Findings

Security bounds for reverse reconciliation are tight.

The model effectively characterizes Gaussian source noise.

Provides a framework for analyzing CV QKD security with source noise.

Abstract

Source noise affects the security of continuous-variable quantum key distribution (CV QKD), and is diffcult to analyze. We propose a model to characterize Gaussian source noise through introducing a neutral party (Fred) who induces the noise with a general unitary transformation. Without knowing Fred's exact state, we derive the security bounds for both reverse and direct reconciliations and show that the bound for reverse reconciliation is tight.