Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Chinese Physics B

Phase-matching quantum key distribution with light source monitoring

Wenting Li, Le Wang, Wei Li, Shengmei Zhao

Published Dec 8, 2021• 3 citations
Publisher

Abstract

The transmission loss of photons during quantum key distribution (QKD) process leads to the linear key rate bound for practical QKD systems without quantum repeaters. Phase matching quantum key distribution (PM-QKD) protocol, an novel QKD protocol, can overcome the constraint with a measurement-device-independent structure, while it still requires the light source to be ideal. This assumption is not guaranteed in practice, leading to practical secure issues. In this paper, we propose a modified PM-QKD protocol with a light source monitoring, named PM-QKD-LSM protocol, which can guarantee the security of the system under the non-ideal source condition. The results show that our proposed protocol performs almost the same as the ideal PM-QKD protocol even considering the imperfect factors in practical systems. PM-QKD-LSM protocol has a better performance with source fluctuation, and it is robust in symmetric or asymmetric cases.

DOI
10.1088/1674-1056/ac4101

Related papers

Mode pairing quantum key distribution with light source monitoring

Zhenhua Li, Tianqi Dou, Yuheng Xie +9 more

Abstract Mode pairing quantum key distribution (MP-QKD) overcomes the repeaterless bound without requiring phase locking and phase tracking. However, MP-QKD still assumes that the light source is trusted, which can present challenges in practical deployments and potentially introduce security vulnerabilities. In this paper, we propose a light source monitoring (LSM) scheme that guarantees the security of MP-QKD with the untrusted light sources. The simulation results demonstrate that, when considering untrusted light sources, the performance of MP-QKD with the LSM scheme remains nearly identical to that of ideal MP-QKD, even in the presence of the source fluctuations. Furthermore, we simplify some of the complex integration calculations involved in simulating the observed quantities of MP-QKD, which reduces the running time of the parameter optimization procedure.

New Journal of Physics•Aug 28, 2024•2 citations

Decoy-state phase-matching quantum key distribution with source errors

Yang Yu, Le Wang, Shengmei Zhao +1 more

The phase-matching quantum key distribution (PM-QKD), one of the variants of Twin-Field (TF) QKD protocol, was recently proposed to overcome the rate-distance limits of point to point protocol without quantum repeaters. In this paper, we propose a more practical PM-QKD protocol version with four-intensity decoy states and source errors, since neither the infinite decoy states nor the precise control of the light source is available in practice. We present the formulation of the secure key rate of the proposed protocol and analyze the performances of the protocol with and without source errors by numerical simulations.

Optics Express•Dec 6, 2020•14 citations

Finite-key analysis of asymmetric phase-matching quantum key distribution with unstable sources

Xiaoxu Zhang, Yang Wang, Mu-Sheng Jiang +3 more

The twin-field quantum key distribution (TF-QKD) protocol has been studied widely to overcome the linear bound, and several variations of the TF-QKD protocol have been proposed to improve security and practicality. One variation called the phase-matching QKD (PM-QKD) protocol develops an optical-mode-based security; simultaneously, it has a quadratic improvement of key rate without either basis choice or phase locking. So far, the main research work of the PM-QKD protocol has focused on symmetric channels. However, it is quite common that the two channels have asymmetric transmittances in real life. In this paper, we discuss the effects of asymmetric channels on the PM-QKD protocol; to reach a much better performance and achieve a higher key rate, the intensity must be optimized to compensate for channel asymmetry. We also study the practical issues of finite-key effects and intensity fluctuations, which have significant effects on the key rate of PM-QKD.

Journal of the Optical Society of America B•Jan 11, 2021•6 citations

Monitoring an untrusted light source with single-photon detectors in measurement-device-independent quantum key distribution

Yucheng Qiao, Gan Wang, Zhengyu Li +2 more

Measurement-device-independent quantum key distribution (MDI-QKD) is proposed to close the loopholes of the detection part in QKD systems, while it still requires the light source to be trusted. This assumption is not guaranteed in practice, leading to practical secure issues. In this paper, we propose a light source monitoring scheme with single-photon detectors for MDI-QKD, which can guarantee the security of the system under the untrusted source condition with both common decoy state method and the newly proposed five-intensity decoy state method. Moreover, our monitoring scheme performs almost the same as the ideal MDI protocol even considering the imperfect factors in practical systems. Compared to the previous scheme, our work improves the secure key rate and the transmission distance of practical MDI-QKD systems significantly.

Physical Review A•May 3, 2019•13 citations

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

Xuerui Qian, Chunhui Zhang, Hua-Wei Yuan +3 more

Twin-field quantum key distribution (TF-QKD) can break the repeaterless linear bound and possess the measurement-device-independent security, and thus seems very promising in practical applications of quantum secure communication. In most reported TF-QKD protocols, light sources are assumed to possess trusted and fixed photon number distributions (PND), which are unrealistic assumptions in practical applications. Fortunately, the light source monitoring (LSM) method is proposed to circumvent this problem by actively adjusting the attenuation coefficient and monitoring the photon number distribution of light sources. However, the active light source monitoring (ALSM) method may induce additional modulation errors due to imperfect attenuation devices, deteriorating practical performances of TF-QKD systems. In this manuscript, we propose a passive light source monitoring (PLSM) scheme for TF-QKD, and employ the sending-or-not-sending (SNS) TF-QKD as an example for illustration. Simulation results show that our present work can greatly exceed both the original SNS protocol and the ALSM scheme when light source fluctuations and modulation errors are taken into account.

Entropy•Apr 23, 2022•2 citations

Free-Space Phase-Matching Quantum Key Distribution

Yang Yu, Le Wang, Shengmei Zhao +1 more

As a practical version of twin-field quantum key distribution (TF-QKD), phase-matching quantum key distribution (PM-QKD) is able to surpass the linear bound without quantum repeaters. Implementing PM-QKD through free space can guarantee two parties to share unconditionally secure keys between ground stations and mobile platforms. However, atmospheric turbulence decreases the free-space secure key rate as the result of fluctuations of transmittances caused by it. This paper includes two works we do. First, for generality, we derive the secure key rate formula of 4-intensity PM-QKD based on asymmetric channel transmittances. Second, we numerically simulate the performance of PM-QKD in free space and ideal circumstance to study the effect of the atmospheric turbulence.

International Conference on Wireless Communications and Signal Processing (WCSP)•Oct 20, 2021•2 citations
The transmission loss of photons during quantum key distribution (QKD) process leads to the linear key rate bound for practical QKD systems without quantum repeaters. Phase matching quantum key distribution (PM-QKD) protocol, an novel QKD protocol, can overcome the constraint with a measurement-device-independent structure, while it still requires the light source to be ideal. This assumption is not guaranteed in practice, leading to practical secure issues. In this paper, we propose a modified PM-QKD protocol with a light source monitoring, named PM-QKD-LSM protocol, which can guarantee the security of the system under the non-ideal source condition. The results show that our proposed protocol performs almost the same as the ideal PM-QKD protocol even considering the imperfect factors in practical systems. PM-QKD-LSM protocol has a better performance with source fluctuation, and it is robust in symmetric or asymmetric cases.
Abstract Mode pairing quantum key distribution (MP-QKD) overcomes the repeaterless bound without requiring phase locking and phase tracking. However, MP-QKD still assumes that the light source is trusted, which can present challenges in practical deployments and potentially introduce security vulnerabilities. In this paper, we propose a light source monitoring (LSM) scheme that guarantees the security of MP-QKD with the untrusted light sources. The simulation results demonstrate that, when considering untrusted light sources, the performance of MP-QKD with the LSM scheme remains nearly identical to that of ideal MP-QKD, even in the presence of the source fluctuations. Furthermore, we simplify some of the complex integration calculations involved in simulating the observed quantities of MP-QKD, which reduces the running time of the parameter optimization procedure.
The phase-matching quantum key distribution (PM-QKD), one of the variants of Twin-Field (TF) QKD protocol, was recently proposed to overcome the rate-distance limits of point to point protocol without quantum repeaters. In this paper, we propose a more practical PM-QKD protocol version with four-intensity decoy states and source errors, since neither the infinite decoy states nor the precise control of the light source is available in practice. We present the formulation of the secure key rate of the proposed protocol and analyze the performances of the protocol with and without source errors by numerical simulations.
The twin-field quantum key distribution (TF-QKD) protocol has been studied widely to overcome the linear bound, and several variations of the TF-QKD protocol have been proposed to improve security and practicality. One variation called the phase-matching QKD (PM-QKD) protocol develops an optical-mode-based security; simultaneously, it has a quadratic improvement of key rate without either basis choice or phase locking. So far, the main research work of the PM-QKD protocol has focused on symmetric channels. However, it is quite common that the two channels have asymmetric transmittances in real life. In this paper, we discuss the effects of asymmetric channels on the PM-QKD protocol; to reach a much better performance and achieve a higher key rate, the intensity must be optimized to compensate for channel asymmetry. We also study the practical issues of finite-key effects and intensity fluctuations, which have significant effects on the key rate of PM-QKD.
Measurement-device-independent quantum key distribution (MDI-QKD) is proposed to close the loopholes of the detection part in QKD systems, while it still requires the light source to be trusted. This assumption is not guaranteed in practice, leading to practical secure issues. In this paper, we propose a light source monitoring scheme with single-photon detectors for MDI-QKD, which can guarantee the security of the system under the untrusted source condition with both common decoy state method and the newly proposed five-intensity decoy state method. Moreover, our monitoring scheme performs almost the same as the ideal MDI protocol even considering the imperfect factors in practical systems. Compared to the previous scheme, our work improves the secure key rate and the transmission distance of practical MDI-QKD systems significantly.
Twin-field quantum key distribution (TF-QKD) can break the repeaterless linear bound and possess the measurement-device-independent security, and thus seems very promising in practical applications of quantum secure communication. In most reported TF-QKD protocols, light sources are assumed to possess trusted and fixed photon number distributions (PND), which are unrealistic assumptions in practical applications. Fortunately, the light source monitoring (LSM) method is proposed to circumvent this problem by actively adjusting the attenuation coefficient and monitoring the photon number distribution of light sources. However, the active light source monitoring (ALSM) method may induce additional modulation errors due to imperfect attenuation devices, deteriorating practical performances of TF-QKD systems. In this manuscript, we propose a passive light source monitoring (PLSM) scheme for TF-QKD, and employ the sending-or-not-sending (SNS) TF-QKD as an example for illustration. Simulation results show that our present work can greatly exceed both the original SNS protocol and the ALSM scheme when light source fluctuations and modulation errors are taken into account.
As a practical version of twin-field quantum key distribution (TF-QKD), phase-matching quantum key distribution (PM-QKD) is able to surpass the linear bound without quantum repeaters. Implementing PM-QKD through free space can guarantee two parties to share unconditionally secure keys between ground stations and mobile platforms. However, atmospheric turbulence decreases the free-space secure key rate as the result of fluctuations of transmittances caused by it. This paper includes two works we do. First, for generality, we derive the secure key rate formula of 4-intensity PM-QKD based on asymmetric channel transmittances. Second, we numerically simulate the performance of PM-QKD in free space and ideal circumstance to study the effect of the atmospheric turbulence.