Quantum Key Distribution using Continuous-variable non-Gaussian States

TL;DR

This paper introduces a quantum key distribution protocol utilizing continuous-variable non-Gaussian states, demonstrating improved security and key rates over traditional coherent state protocols against specific eavesdropping attacks.

Contribution

It presents a novel QKD protocol using PASCS states with analysis showing enhanced security and key rate compared to coherent states under certain attack models.

Findings

PASCS states increase secret key rate in lossy channels.

PASCS reduce Eve's attack efficiency in intercept-resend scenarios.

Protocol outperforms coherent state-based QKD in tested attacks.

Abstract

In this work we present a quantum key distribution protocol using continuous-variable non-Gaussian states, homodyne detection and post-selection. The employed signal states are the Photon Added then Subtracted Coherent States (PASCS) in which one photon is added and subsequently one photon is subtracted. We analyze the performance of our protocol, compared to a coherent state based protocol, for two different attacks that could be carried out by the eavesdropper (Eve). We calculate the secret key rate transmission in a lossy line for a superior channel (beam-splitter) attack, and we show that we may increase the secret key generation rate by using the non-Gaussian PASCS rather than coherent states. We also consider the simultaneous quadrature measurement (intercept-resend) attack and we show that the efficiency of Eve's attack is substantially reduced if PASCS are used as signal states.