scholarly journals Discrete-variable quantum key distribution with homodyne detection

Quantum ◽  
2022 ◽  
Vol 6 ◽  
pp. 613
Author(s):  
Ignatius William Primaatmaja ◽  
Cassey Crystania Liang ◽  
Gong Zhang ◽  
Jing Yan Haw ◽  
Chao Wang ◽  
...  
Keyword(s):  
Quantum Key Distribution ◽  
High Speed ◽  
Cost Effective ◽  
Key Distribution ◽  
Continuous Variable ◽  
Discrete Variable ◽  
Quantum State Preparation ◽  
High Bandwidth ◽  
The Cost ◽  
Selection Of

Most quantum key distribution (QKD) protocols can be classified as either a discrete-variable (DV) protocol or continuous-variable (CV) protocol, based on how classical information is being encoded. We propose a protocol that combines the best of both worlds – the simplicity of quantum state preparation in DV-QKD together with the cost-effective and high-bandwidth of homodyne detectors used in CV-QKD. Our proposed protocol has two highly practical features: (1) it does not require the honest parties to share the same reference phase (as required in CV-QKD) and (2) the selection of decoding basis can be performed after measurement. We also prove the security of the proposed protocol in the asymptotic limit under the assumption of collective attacks. Our simulation suggests that the protocol is suitable for secure and high-speed practical key distribution over metropolitan distances.

Comprehensive high-speed reconciliation for continuous-variable quantum key distribution

2020 ◽  
Vol 19 (9) ◽  
Author(s):  
Dabo Guo ◽  
Chao He ◽  
Tianhao Guo ◽  
Zhe Xue ◽  
Qiang Feng ◽  
...  
Keyword(s):  
Quantum Key Distribution ◽  
High Speed ◽  
Key Distribution ◽  
Continuous Variable

High-speed continuous-variable quantum key distribution without sending a local oscillator

2015 ◽  
Vol 40 (16) ◽  
pp. 3695 ◽  
Author(s):  
Duan Huang ◽  
Peng Huang ◽  
Dakai Lin ◽  
Chao Wang ◽  
Guihua Zeng
Keyword(s):  
Quantum Key Distribution ◽  
High Speed ◽  
Key Distribution ◽  
Local Oscillator ◽  
Continuous Variable

High performance reconciliation for continuous-variable quantum key distribution with LDPC code

2015 ◽  
Vol 13 (02) ◽  
pp. 1550010 ◽  
Author(s):  
Dakai Lin ◽  
Duan Huang ◽  
Peng Huang ◽  
Jinye Peng ◽  
Guihua Zeng
Keyword(s):  
Quantum Key Distribution ◽  
Secure Communication ◽  
High Speed ◽  
High Performance ◽  
Graphics Processing Unit ◽  
Ldpc Code ◽  
Key Distribution ◽  
Continuous Variable ◽  
Processing Unit ◽  
Secret Key

Reconciliation is a significant procedure in a continuous-variable quantum key distribution (CV-QKD) system. It is employed to extract secure secret key from the resulted string through quantum channel between two users. However, the efficiency and the speed of previous reconciliation algorithms are low. These problems limit the secure communication distance and the secure key rate of CV-QKD systems. In this paper, we proposed a high-speed reconciliation algorithm through employing a well-structured decoding scheme based on low density parity-check (LDPC) code. The complexity of the proposed algorithm is reduced obviously. By using a graphics processing unit (GPU) device, our method may reach a reconciliation speed of 25 Mb/s for a CV-QKD system, which is currently the highest level and paves the way to high-speed CV-QKD.

scholarly journals CV-MDI quantum key distribution via satellite

2017 ◽  
Vol 17 (5&6) ◽  
pp. 361-379
Author(s):  
Nedasadat Hosseinidehaj ◽  
Robert Malaney
Keyword(s):  
Fading Channels ◽  
Quantum Key Distribution ◽  
Positive Impact ◽  
Key Distribution ◽  
Continuous Variable ◽  
Key Generation ◽  
Measurement Device ◽  
High Loss ◽  
The Status ◽  
The Cost

In this work we analyze a measurement-device-independent (MDI) protocol to establish continuous-variable (CV) quantum key distribution (QKD) between two ground stations. We assume communication occurs between the ground stations via satellite over two independent atmospheric-fading channels influenced by turbulence-induced beam wandering. In this MDI protocol the measurement device is the satellite itself, and the security of the protocol is analyzed through an equivalent entanglement-based swapping scheme. We quantify the positive impact the fading channels can have on the final quantum key rates, demonstrating how the protocol is able to generate a positive key rate even over high-loss atmospheric channels provided that the maximum transmission coefficient of the channel is sufficiently large. This is somewhat counter-intuitive given that the same outcome is only possible in the low-loss regime for a measurement device centrally positioned in a fiber-optic channel. Our results show that useful space-based quantum key generation rates between two ground stations are possible even when the relay satellite is held by an adversary. The cost in key rate incurred by altering the status of the satellite from trustworthy to untrustworthy is presented.

scholarly journals Simple security proofs for continuous variable quantum key distribution with intensity fluctuating sources

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Chenyang Li ◽  
Li Qian ◽  
Hoi-Kwong Lo
Keyword(s):  
Quantum Key Distribution ◽  
Distribution Systems ◽  
Finite Size ◽  
Key Distribution ◽  
Continuous Variable ◽  
Discrete Variable ◽  
Security Proofs ◽  
Security Proof ◽  
Main Technique ◽  
Secret Keys

AbstractDespite tremendous theoretical and experimental progress in continuous variable (CV) quantum key distribution (QKD), the security has not been rigorously established for most current continuous variable quantum key distribution systems that have imperfections. Among these imperfections, intensity fluctuation is one of the principal problems affecting security. In this paper, we provide simple security proofs for continuous variable quantum key distribution systems with intensity fluctuating sources. Specifically, depending on device assumptions in the source, the imperfect systems are divided into two general cases for security proofs. In the most conservative case, we prove the security based on the tagging idea, which is a main technique for the security proof of discrete variable quantum key distribution. Our proofs are simple to implement without any hardware adjustment for current continuous variable quantum key distribution systems. Also, we show that our proofs are able to provide secure secret keys in the finite-size scenario.

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