scholarly journals Noiseless Attenuation for Continuous-Variable Quantum Key Distribution over Ground-Satellite Uplink

2021 ◽  
Vol 11 (23) ◽  
pp. 11289
Author(s):  
Shengjie Xu ◽  
Yin Li ◽  
Yijun Wang ◽  
Yun Mao ◽  
Zhiyue Zuo ◽  
...  
Keyword(s):  
Quantum Key Distribution ◽  
Finite Size ◽  
Key Distribution ◽  
Continuous Variable ◽  
Transmission Efficiency ◽  
Global Network ◽  
Finite Size Effect ◽  
Communication Time ◽  
Source Preparation ◽  
Security Bound

Satellite-based quantum key distribution (QKD) has lately received considerable attention due to its potential to establish a secure global network. Associated with its application is a turbulent atmosphere that sets a notable restriction to the transmission efficiency, which is especially challenging for ground-to-satellite uplink scenarios. Here, we propose a novel noiseless attenuation (NA) scheme involving a zero-photon catalysis operation for source preparation to improve the performance of continuous-variable (CV) QKD over uplink. Numerical analysis shows that the NA-based CV-QKD, under attenuation optimization, outperforms the traditional CV-QKD, which is embodied in extending the allowable zenith angle while improving the effective communication time. Attributing to characteristics of the attenuation optimization, we find that the NA-involved source preparation improves the security bound by relatively reducing the amount of information available to eavesdroppers. Taking the finite-size effect into account, we achieve a tighter bond of security, which is more practical compared with the asymptotic limit.

scholarly journals Photon Subtraction-Induced Plug-and-Play Scheme for Enhancing Continuous-Variable Quantum Key Distribution with Discrete Modulation

2020 ◽  
Vol 10 (12) ◽  
pp. 4175
Author(s):  
Chao Yu ◽  
Shanhua Zou ◽  
Yun Mao ◽  
Ying Guo
Keyword(s):  
Quantum Key Distribution ◽  
Communication Systems ◽  
Finite Size ◽  
Key Distribution ◽  
Continuous Variable ◽  
Finite Size Effect ◽  
Secret Key ◽  
Long Distance ◽  
Plug And Play ◽  
Photon Subtraction

Establishing high-rate secure communications is a potential application of continuous-variable quantum key distribution (CVQKD) but still challenging for the long-distance transmission technology compatible with modern optical communication systems. Here, we propose a photon subtraction-induced plug-and-play scheme for enhancing CVQKD with discrete-modulation (DM), avoiding the traditional loopholes opened by the transmission of local oscillator. A photon subtraction operation is involved in the plug-and-play scheme for detection while resisting the extra untrusted source noise of the DM-CVQKD system. We analyze the relationship between secret key rate, channel losses, and untrusted source noise. The simulation result shows that the photon-subtracted scheme enhances the performance in terms of the maximal transmission distance and make up for the deficiency of the original system effectively. Furthermore, we demonstrate the influence of finite-size effect on the secret key rate which is close to the practical implementation.

scholarly journals Security Analysis of a Passive Continuous-Variable Quantum Key Distribution by Considering Finite-Size Effect

Entropy ◽  
2021 ◽  
Vol 23 (12) ◽  
pp. 1698
Author(s):  
Shengjie Xu ◽  
Yin Li ◽  
Yijun Wang ◽  
Yun Mao ◽  
Xiaodong Wu ◽  
...  
Keyword(s):  
Size Effect ◽  
Quantum Key Distribution ◽  
Photon Number ◽  
Security Analysis ◽  
Great Influence ◽  
Finite Size ◽  
Key Distribution ◽  
Continuous Variable ◽  
Finite Size Effect ◽  
Size Regime

We perform security analysis of a passive continuous-variable quantum key distribution (CV-QKD) protocol by considering the finite-size effect. In the passive CV-QKD scheme, Alice utilizes thermal sources to passively make preparation of quantum state without Gaussian modulations. With this technique, the quantum states can be prepared precisely to match the high transmission rate. Here, both asymptotic regime and finite-size regime are considered to make a comparison. In the finite-size scenario, we illustrate the passive CV-QKD protocol against collective attacks. Simulation results show that the performance of passive CV-QKD protocol in the finite-size case is more pessimistic than that achieved in the asymptotic case, which indicates that the finite-size effect has a great influence on the performance of the single-mode passive CV-QKD protocol. However, we can still obtain a reasonable performance in the finite-size regime by enhancing the average photon number of the thermal state.

scholarly journals Virtual zero-photon catalysis for improving continuous-variable quantum key distribution via Gaussian post-selection

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hai Zhong ◽  
Ying Guo ◽  
Yun Mao ◽  
Wei Ye ◽  
Duan Huang
Keyword(s):  
Quantum Key Distribution ◽  
Finite Size ◽  
Key Distribution ◽  
Continuous Variable ◽  
Point Of View ◽  
Excess Noise ◽  
Finite Size Effect ◽  
Practical Implementation ◽  
Transmission Distance ◽  
Improvement Effect

Abstract Quantum catalysis is a feasible approach to increase the performance of continuous-variable quantum key distribution (CVQKD), involving the special zero-photon catalysis (ZPC) operation. However, in the practical point of view, the improvement effect of this operation will be limited by the imperfection of the photon detector. In this paper, we show that the ZPC operation at the sender can be simulated by a post-selection method without implementing it in practical devices. While performing this virtual version of ZPC in CVQKD, we can not only reach the ideal case of its practical implementation with minimal hardware requirement, but also keep the benefit of Gaussian security proofs. Based on Gaussian modulated coherent state protocols with achievable parameters, we enhance the security of the proposed scheme from the asymptotical case to the finite-size scenario and composable framework. Simulation results show that similar to the asymptotical case, both the maximal transmission distance and the tolerable excess noise of virtual ZPC-involved CVQKD outperform the original scheme and the scheme using virtual photon subtraction while considering finite-size effect and composable security. In addition, the virtual ZPC-involved CVQKD can tolerate a higher imperfection of the detector, enabling its practical implementation of the CVQKD system with state-of-the-art technology.

scholarly journals Security Analysis of Discrete-Modulated Continuous-Variable Quantum Key Distribution over Seawater Channel

2019 ◽  
Vol 9 (22) ◽  
pp. 4956 ◽  
Author(s):  
Xinchao Ruan ◽  
Hang Zhang ◽  
Wei Zhao ◽  
Xiaoxue Wang ◽  
Xuan Li ◽  
...  
Keyword(s):  
Quantum Key Distribution ◽  
Secure Communication ◽  
Security Analysis ◽  
Finite Size ◽  
Key Distribution ◽  
Continuous Variable ◽  
Heterodyne Detection ◽  
Secret Key ◽  
Transmission Distance ◽  
Better Than

We investigate the optical absorption and scattering properties of four different kinds of seawater as the quantum channel. The models of discrete-modulated continuous-variable quantum key distribution (CV-QKD) in free-space seawater channel are briefly described, and the performance of the four-state protocol and the eight-state protocol in asymptotic and finite-size cases is analyzed in detail. Simulation results illustrate that the more complex is the seawater composition, the worse is the performance of the protocol. For different types of seawater channels, we can improve the performance of the protocol by selecting different optimal modulation variances and controlling the extra noise on the channel. Besides, we can find that the performance of the eight-state protocol is better than that of the four-state protocol, and there is little difference between homodyne detection and heterodyne detection. Although the secret key rate of the protocol that we propose is still relatively low and the maximum transmission distance is only a few hundred meters, the research on CV-QKD over the seawater channel is of great significance, which provides a new idea for the construction of global secure communication network.

Finite-size analysis of continuous-variable quantum key distribution with entanglement in the middle

2019 ◽  
Vol 28 (1) ◽  
pp. 010305 ◽  
Author(s):  
Ying Guo ◽  
Yu Su ◽  
Jian Zhou ◽  
Ling Zhang ◽  
Duan Huang
Keyword(s):  
Quantum Key Distribution ◽  
Finite Size ◽  
Key Distribution ◽  
Continuous Variable ◽  
Size Analysis

scholarly journals Discrete Modulation Source Enhancement for Continuous Variable Quantum Key Distribution through Photon Catalyzing

2020 ◽  
Author(s):  
Zhengchun Zhou ◽  
Shanhua Zou ◽  
Yun Mao ◽  
Tongcheng Huang ◽  
Ying Guo
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Continuous Variable ◽  
High Rate ◽  
Practical Implementation ◽  
Statistical Fluctuation ◽  
Secret Key ◽  
Long Distance ◽  
Transmission Distance ◽  
Source Preparation

Establishing global high-rate secure communications is a potential application of continuous-variable quantum key distribution (CVQKD) but also challenging for long-distance transmissions in metropolitan areas. The discrete modulation(DM) can make up for the shortage of transmission distance that has a unique advantage against all side-channel attacks, however its further performance improvement requires source preparation in the presence of noise and loss. Here, we consider the effects of photon catalysis (PC) on the DM-involved source preparation for lengthening the maximal transmission distance of the CVQKD system. We address a zero-photon catalysis (ZPC)-based source preparation for enhancing the DM-CVQKD system. The statistical fluctuation due to the finite length of data is taken into account for the practical security analysis. Numerical simulations show that the ZPC-based DM-CVQKD system can not only achieve the extended maximal transmission distance, but also contributes to the reasonable increase of the secret key rate. This approach enables the DM-CVQKD to tolerate lower reconciliation efficiency, which may promote the practical implementation solutions compatible with classical optical communications using state-of-the-art technology.

scholarly journals Finite-size security of continuous-variable quantum key distribution with digital signal processing

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Takaya Matsuura ◽  
Kento Maeda ◽  
Toshihiko Sasaki ◽  
Masato Koashi
Keyword(s):  
Signal Processing ◽  
Wavelength Division Multiplexing ◽  
Quantum Key Distribution ◽  
Finite Size ◽  
Digital Signal ◽  
Key Distribution ◽  
Continuous Variable ◽  
Wavelength Division ◽  
Security Proof ◽  
Proof Techniques

AbstractIn comparison to conventional discrete-variable (DV) quantum key distribution (QKD), continuous-variable (CV) QKD with homodyne/heterodyne measurements has distinct advantages of lower-cost implementation and affinity to wavelength division multiplexing. On the other hand, its continuous nature makes it harder to accommodate to practical signal processing, which is always discretized, leading to lack of complete security proofs so far. Here we propose a tight and robust method of estimating fidelity of an optical pulse to a coherent state via heterodyne measurements. We then construct a binary phase modulated CV-QKD protocol and prove its security in the finite-key-size regime against general coherent attacks, based on proof techniques of DV QKD. Such a complete security proof is indispensable for exploiting the benefits of CV QKD.

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