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

Entropy ◽  
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.

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.

Phase-matching quantum key distribution with light source monitoring

2021 ◽  
Author(s):  
Wen-Ting Li ◽  
Le Wang ◽  
Wei Li ◽  
Sheng-Mei Zhao
Keyword(s):  
Light Source ◽  
Quantum Key Distribution ◽  
Source Monitoring ◽  
Transmission Loss ◽  
Key Distribution ◽  
Phase Matching ◽  
Measurement Device ◽  
Source Condition ◽  
Source Fluctuation ◽  
The Ideal

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.

The security of SARG04 protocol in plug and play QKD system with an untrusted source

2012 ◽  
Vol 12 (7&8) ◽  
pp. 630-647
Author(s):  
Bingjie Xu ◽  
Xiang Peng ◽  
Hong Guo
Keyword(s):  
Quantum Key Distribution ◽  
Source Monitoring ◽  
Photon Number ◽  
Key Distribution ◽  
Statistical Fluctuation ◽  
Statistical Parameters ◽  
Plug And Play ◽  
Monitoring Process ◽  
Simulation Results

The SARG04 protocol is one of the most frequently used protocol in commercial plug-and-play quantum key distribution (QKD) system, where an eavesdropper can completely control or change the photon number statistics of the QKD source. To ensure the security of SARG04 protocol in plug-and-play QKD system with an unknown and untrusted source, the bounds of a few statistical parameters of the source need to be monitored. An active or a passive source monitor schemes are proposed to verify these parameters. Furthermore, the practical issues due to statistical fluctuation and detection noise in the source monitoring process are quantitatively analyzed. Our simulation results show that the passive scheme can be efficiently applied to plug-and-play system with SARG04 protocol.

scholarly journals Security analysis of the time-coding quantum key distribution protocols

2011 ◽  
Vol 11 (11&12) ◽  
pp. 968-987
Author(s):  
Thierry Debuisschert ◽  
Simon Fossier
Keyword(s):  
Mathematical Model ◽  
Quantum Key Distribution ◽  
Single Photon ◽  
Photon Number ◽  
Security Analysis ◽  
Key Distribution ◽  
Low Noise ◽  
Photon Detectors ◽  
Single Photon Detectors ◽  
Time Coding

We report the security analysis of time-coding quantum key distribution protocols. The protocols make use of coherent single-photon pulses. The key is encoded in the photon time-detection. The use of coherent superposition of states allows to detect eavesdropping of the key. We give a mathematical model of a first protocol from which we derive a second, simpler, protocol. We derive the security analysis of both protocols and find that the secure rates can be similar to those obtained with the BB84 protocol. We then calculate the secure distance for those protocols over standard fibre links. When using low-noise superconducting single photon detectors, secure distances over 200 km can be foreseen. Finally, we analyse the consequences of photon-number splitting attacks when faint pulses are used instead of single photon pulses. A decoy states technique can be used to prevent such attacks.

scholarly journals Testing the photon-number statistics of a quantum key distribution light source

2018 ◽  
Vol 26 (18) ◽  
pp. 22733 ◽  
Author(s):  
J. F. Dynes ◽  
M. Lucamarini ◽  
K. A. Patel ◽  
A. W. Sharpe ◽  
M. B. Ward ◽  
...  
Keyword(s):  
Light Source ◽  
Quantum Key Distribution ◽  
Photon Number ◽  
Key Distribution

scholarly journals Security of practical phase-coding quantum key distribution

2010 ◽  
Vol 10 (9&10) ◽  
pp. 771-779
Author(s):  
Hong-Wei Li ◽  
Zheng-Qiang Yin ◽  
Zheng-Fu Han ◽  
Wan-Su Bao ◽  
Guang-Can Guo
Keyword(s):  
Quantum Key Distribution ◽  
Security Analysis ◽  
Real Life ◽  
Key Distribution ◽  
The State ◽  
Zehnder Interferometer ◽  
Secret Key ◽  
Phase Coding ◽  
Active Compensation ◽  
Security Proof

Security proof of practical quantum key distribution (QKD) has attracted a lot of attentions in recent years. Most of real-life QKD implementations are based on phase-coding BB84 protocol, which usually use Unbalanced Mach-Zehnder Interferometer (UMZI) as the information encoder and decoder. However, the long arm and short arm of UMZI will introduce different loss in practical experimental realizations, the state emitted by Alice's side is nolonger perfect BB84 states correspondingly. In this paper, we will give the security analysis in this situation. Counterintuitively, active compensation for this different loss will only lower the secret key bit rate.

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 Unidimensional Two-Way Continuous-Variable Quantum Key Distribution Using Coherent States

Entropy ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 294
Author(s):  
Yiming Bian ◽  
Luyu Huang ◽  
Yichen Zhang
Keyword(s):  
Quantum Key Distribution ◽  
Coherent States ◽  
Security Analysis ◽  
Key Distribution ◽  
Continuous Variable ◽  
Excess Noise ◽  
Transmission Distance ◽  
Fixed Distance ◽  
The One ◽  
Attack Strategy

We propose a unidimensional two-way continuous-variable quantum key distribution protocol with coherent states, where the sender modulates a single quadrature of the coherent states rather than both quadratures to simplify the structure of a two-way system. Security analysis is performed with a general attack strategy, known as two-mode attack, which helps to reduce limitations in the analysis. The performance of the protocol under all accessible two-mode attacks at fixed distance is illustrated. Further, two typical two-mode attack strategies are obtained from it, which are one-mode attack strategy and optimal two-mode attack strategy. Between them, the one-mode attack is the simplest form of the two-mode attack, while the optimal two-mode attack is the most complicated one. Simulations show that though the system is simplified, the performance of the two-way protocol with unidimensional modulation is still comparable to that of the counterpart with Gaussian modulation even against the optimal two-mode attack when Eve’s ability is maximized. Thus, the proposed protocol simplifies the two-way system while guaranteeing its performance to a certain extent. Especially in a practical system with short transmission distance and high excess noise, the protocol has a good application prospect.

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