Improvement of the safe transmission distance via optimization of the photon number distribution for the faint optical pulse in practical quantum key distribution systems

The safety of the six-state scheme in the practical communication systems was studied based on an effective eavesdropping method, which called path attacks adopted by eavesdroppers. In the practical systems, eavesdropper can select appropriate path to eavesdrop on legitimate users to obtain some information. This method will keep photon number distribution in the laser pulses, and the eavesdropper can be hidden by the losses of quantum channel without being detected. The results show that eavesdropper can get more information with the increase of transmission distance and the average number of photons.

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Sending-or-Not-Sending Twin-Field Quantum Key Distribution with Light Source Monitoring

Entropy ◽

10.3390/e22010036 ◽

2019 ◽

Vol 22 (1) ◽

pp. 36

Author(s):

Yucheng Qiao ◽

Ziyang Chen ◽

Yichen Zhang ◽

Bingjie Xu ◽

Hong Guo

Keyword(s):

Light Source ◽

Quantum Key Distribution ◽

Source Monitoring ◽

Selection Process ◽

Photon Number ◽

Security Analysis ◽

Real Life ◽

Key Distribution ◽

Transmission Distance ◽

Security Problem

Twin-field quantum key distribution (TF-QKD) is proposed to achieve a remote key distribution with a maximum secure transmission distance up to over 500 km. Although the security of TF-QKD in its detection part is guaranteed, there are some remaining problems in the source part. The sending-or-not-sending (SNS) protocol is proposed to solve the security problem in the phase post-selection process; however, the light source is still assumed to be an ideal coherent state. This assumption is not satisfied in real-life QKD systems, leading to practical secure issues. In this paper, we discuss the condition that the photon number distribution (PND) of the source is unknown for the SNS protocol, demonstrate that the security analysis is still valid under a source with unknown PND, and show that with light source monitoring, the performance of the SNS protocol can remain almost unchanged.

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Improving the Performance of Practical Quantum Key Distribution With Advantage Distillation Technology

10.21203/rs.3.rs-753036/v1 ◽

2021 ◽

Author(s):

Hong-Wei Li ◽

Chun-Mei Zhang ◽

Mu-Sheng Jiang ◽

Qing-Yu Cai

Keyword(s):

Distribution System ◽

Quantum Key Distribution ◽

Distribution Systems ◽

Key Distribution ◽

Measurement Device ◽

Transmission Distance ◽

State Measurement ◽

Quantum Step ◽

State Device ◽

Measurement Device Independent

Abstract To improve the maximal transmission distance and the maximal error rate tolerance, we apply the advantage distillation technology to analyze security of the practical decoy-sate quantum key distribution system. Based on the practical experimental parameters, the device-dependent quantum key distribution protocols and the measurement-device-independent quantum key distribution protocols have been respectively analyzed, and our analysis results demonstrate that the advantage distillation technology can significantly improve the performance of different quantum key distribution protocols. In the four-state and six-state device-dependent quantum key distribution protocols, we prove that the maximal transmission distance can be improved from 142 km to 180 km and from 146 km to 187 km respectively. In the four-state and six-state measurement-device-independent quantum key distribution protocols, we prove that the maximal transmission distance can be improved from 195 km to 273 km and from 200 km to 282 km respectively. More interestingly, the advantage distillation technology does not need to change the hardware devices about the quantum step, thus it can be conveniently to be applied in various practical quantum key distribution systems.

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Effects of Photon-Number-Splitting Attacks on the Security of Satellite-to-Ground Quantum Key Distribution Systems

Acta Optica Sinica ◽

10.3788/aos20092911.2989 ◽

2009 ◽

Vol 29 (11) ◽

pp. 2989-2993 ◽

Cited By ~ 1

Author(s):

陈彦 Chen Yan ◽

杨红宇 Yang Hongyu ◽

邓科 Deng Ke

Keyword(s):

Quantum Key Distribution ◽

Distribution Systems ◽

Photon Number ◽

Key Distribution

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

Applied Sciences ◽

10.3390/app9224956 ◽

2019 ◽

Vol 9 (22) ◽

pp. 4956 ◽

Cited By ~ 2

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.

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