scholarly journals Improving the Maximum Transmission Distance of Self-Referenced Continuous-Variable Quantum Key Distribution Using a Noiseless Linear Amplifier

Entropy ◽  
2018 ◽  
Vol 20 (6) ◽  
pp. 461 ◽  
Author(s):  
Yijun Wang ◽  
Xudong Wang ◽  
Duan Huang ◽  
Ying Guo
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Continuous Variable ◽  
Transmission Distance ◽  
Linear Amplifier ◽  
Maximum Transmission

DISCRETELY MODULATED CONTINUOUS-VARIABLE QUANTUM KEY DISTRIBUTION WITH A NONDETERMINISTIC NOISELESS AMPLIFIER

2013 ◽  
Vol 11 (04) ◽  
pp. 1350037 ◽  
Author(s):  
JIAN FANG ◽  
YUAN LU ◽  
PENG HUANG ◽  
GUANGQIANG HE ◽  
GUIHUA ZENG
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Continuous Variable ◽  
Excess Noise ◽  
Secret Key ◽  
Transmission Distance ◽  
Linear Amplifier ◽  
Detection Stage ◽  
Maximum Transmission ◽  
Better Than

In this paper, we first study a generalized protocol of discrete modulation for continuous-variable quantum key distribution with N coherent states in a Gaussian lossy and noisy channel and investigate its performance against collective attacks. We find that discrete modulation protocols with more than eight states do not perform better than the eight-state protocol. Then, we study the improvement of this protocol by using a nondeterministic noiseless linear amplifier (NLA) on Bob's detection stage. Results indicate that a NLA with gain g can extend the maximum transmission distance by 50 log 10g2 km and can increase the maximal tolerable excess noise. With the reconciliation efficiency β, we find the gain of NLA has a maximal value defined as g max and by adjusting the gain to about βg max one can have the best improvement on secret key rate.

scholarly journals Performance Improvement of Discretely Modulated Continuous-Variable Quantum Key Distribution with Untrusted Source via Heralded Hybrid Linear Amplifier

Entropy ◽  
2020 ◽  
Vol 22 (8) ◽  
pp. 882
Author(s):  
Kunlin Zhou ◽  
Xuelin Wu ◽  
Yun Mao ◽  
Zhiya Chen ◽  
Qin Liao ◽  
...  
Keyword(s):  
Communication Networks ◽  
Quantum Key Distribution ◽  
Signal To Noise Ratio ◽  
Key Distribution ◽  
High Gain ◽  
Continuous Variable ◽  
Secret Key ◽  
Transmission Distance ◽  
Linear Amplifier ◽  
Maximum Transmission

In practical quantum communication networks, the scheme of continuous-variable quantum key distribution (CVQKD) faces a challenge that the entangled source is controlled by a malicious eavesdropper, and although it still can generate a positive key rate and security, its performance needs to be improved, especially in secret key rate and maximum transmission distance. In this paper, we proposed a method based on the four-state discrete modulation and a heralded hybrid linear amplifier to enhance the performance of CVQKD where the entangled source originates from malicious eavesdropper. The four-state CVQKD encodes information by nonorthogonal coherent states in phase space. It has better transmission distance than Gaussian modulation counterpart, especially at low signal-to-noise ratio (SNR). Moreover, the hybrid linear amplifier concatenates a deterministic linear amplifier (DLA) and a noiseless linear amplifier (NLA), which can improve the probability of amplification success and reduce the noise penalty caused by the measurement. Furthermore, the hybrid linear amplifier can raise the SNR of CVQKD and tune between two types of performance for high-gain mode and high noise-reduction mode, therefore it can extend the maximal transmission distance while the entangled source is untrusted.

scholarly journals Improving the maximum transmission distance of continuous-variable quantum key distribution using a noiseless amplifier

2014 ◽  
Author(s):  
Rémi Blandino ◽  
Anthony Leverrier ◽  
Marco Barbieri ◽  
Jean Etesse ◽  
Rosa Tualle-Brouri ◽  
...  
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Continuous Variable ◽  
Transmission Distance ◽  
Maximum Transmission

Noise-enhanced CVQKD with untrusted source

2017 ◽  
Vol 31 (16) ◽  
pp. 1750143 ◽  
Author(s):  
Xiaoqun Wang ◽  
Chunhui Huang
Keyword(s):  
Quantum Key Distribution ◽  
Additive Noise ◽  
Key Distribution ◽  
Continuous Variable ◽  
Excess Noise ◽  
Transmission Distance ◽  
Simulation Results ◽  
The Impact ◽  
Maximum Transmission

The performance of one-way and two-way continuous variable quantum key distribution (CVQKD) protocols can be increased by adding some noise on the reconciliation side. In this paper, we propose to add noise at the reconciliation end to improve the performance of CVQKD with untrusted source. We derive the key rate of this case and analyze the impact of the additive noise. The simulation results show that the optimal additive noise can improve the performance of the system in terms of maximum transmission distance and tolerable excess noise.

scholarly journals Improving the maximum transmission distance of continuous-variable quantum key distribution using a noiseless amplifier

2012 ◽  
Vol 86 (1) ◽  
Author(s):  
Rémi Blandino ◽  
Anthony Leverrier ◽  
Marco Barbieri ◽  
Jean Etesse ◽  
Philippe Grangier ◽  
...  
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Continuous Variable ◽  
Transmission Distance ◽  
Maximum Transmission

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.

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