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

Yucheng Qiao; Ziyang Chen; Yichen Zhang; Bingjie Xu; Hong Guo

doi:10.3390/e22010036

Entropy (Dec 2019)

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

Yucheng Qiao,
Ziyang Chen,
Yichen Zhang,
Bingjie Xu,
Hong Guo

Affiliations

Yucheng Qiao: State Key Laboratory of Advanced Optical Communication, Systems and Networks, Department of Electronics, and Center for Quantum Information Technology, Peking University, Beijing 100871, China
Ziyang Chen: State Key Laboratory of Advanced Optical Communication, Systems and Networks, Department of Electronics, and Center for Quantum Information Technology, Peking University, Beijing 100871, China
Yichen Zhang: State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China
Bingjie Xu: Science and Technology on Security Communication Laboratory, Institute of Southwestern Communication, Chengdu 610041, China
Hong Guo: State Key Laboratory of Advanced Optical Communication, Systems and Networks, Department of Electronics, and Center for Quantum Information Technology, Peking University, Beijing 100871, China

DOI: https://doi.org/10.3390/e22010036
Journal volume & issue: Vol. 22, no. 1
p. 36

Abstract

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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.

Published in Entropy

ISSN: 1099-4300 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Science: Astronomy: Astrophysics; Science: Physics
Website: http://www.mdpi.com/journal/entropy

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