Improving Eight-State Continuous Variable Quantum Key Distribution by Applying Photon Subtraction

Qingquan Peng,Ying Guo,Xiaodong Wu

doi:10.3390/app9071333

Qingquan Peng, Ying Guo + Show 1 more

Open Access

https://doi.org/10.3390/app9071333

Copy DOI

Journal: Applied Sciences	Publication Date: Mar 29, 2019
Citations: 3	License type: CC BY 4.0

Affiliation: Central South University, Wuxi Taihu Hospital

Abstract

We propose a new method to effectively improve the performance of a quantum key distribution with eight-state continuous variables by the photon subtraction method. This operation is effective in increasing and distilling Gaussian entanglement between quantum states, and can be easily realized by existing technology. Simulation results show that the channel-loss tolerance of the eight-state continuous variable quantum key distribution (CVQKD) protocol can be extended by the appropriate photon subtraction algorithm; namely, single-photon subtraction.

Highlights

Two independent long-distance legitimate communicators, say, Alice’s station and Bob’s station, can generate an unordered security key sequence through the untrusted quantum and traditional electronic channels by using quantum key distribution (QKD) [1,2]
We need to find the optimal value for Va, because this value will directly determine whether the performance of the eight-state continuous variable quantum key distribution (CVQKD) protocol shows the best performance
This paper presents a method for enhancing the performance of eight-state CVQKD, by use of photon subtraction on the original eight-state CVQKD

Summary

Introduction

Two independent long-distance legitimate communicators, say, Alice’s station and Bob’s station, can generate an unordered security key sequence through the untrusted quantum and traditional electronic channels by using quantum key distribution (QKD) [1,2]. It is worth noting that the current four-state CVQKD has been proven secure during an anti-collective attack, which has been experimentally demonstrated [15,16,17]. Another discretely-modulated scheme, called the eight-state CVQKD, has been proposed, which shows better performance compared with the four-state CVQKD [18,19]. We deployed a photon subtraction operation on Alice’s side, in order to effectively improve the performance of the eight-state protocol. A security analysis shows that the performance of the eight-state protocol can be improved with proper photon subtraction.

Eight-State CVQKD Protocol

Eight-State CVQKD with Photon Subtraction Operation

The Optimal Value

Secret Key Rate

Findings

Performance and Discussion

Conclusions