scholarly journals Proof-of-principle demonstration of semi-quantum key distribution based on the Mirror protocol

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Siyu Han ◽  
Yutao Huang ◽  
Shang Mi ◽  
Xiaojuan Qin ◽  
Jindong Wang ◽  
...  
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Future Research ◽  
Experimental Demonstration ◽  
Phase Encoding ◽  
Quantum Bit ◽  
Selective Modulation ◽  
Secret Keys ◽  
Shared Secret ◽  
Proof Of Principle

AbstractSemi-quantum key distribution (SQKD) is used to establish a string of shared secret keys between a quantum party and a classical party. Here, we report the first proof-of-principle experimental demonstration of SQKD based on the Mirror protocol, which is the most experimentally feasible SQKD protocol, and equipped with time-phase encoding scheme employing the method of selective modulation. The experiment was performed at a repetition frequency of 62.5 MHz and a high raw key rate arrived at 69.8 kbps, and the average quantum bit error rate was found to be 4.56% and 2.78% for the “SWAP-x-Z” ($\mathrm{x}\in \{01,10\}$ x ∈ { 01 , 10 } ) and the “CTRL-X”, respectively. The results demonstrate the feasibility of our system, and this study is helpful for future research on SQKD experiments.

Proof-of-principle experimental demonstration of quantum secure imaging based on quantum key distribution

2019 ◽  
Vol 28 (10) ◽  
pp. 104203
Author(s):  
Yi-Bo Zhao ◽  
Wan-Li Zhang ◽  
Dong Wang ◽  
Xiao-Tian Song ◽  
Liang-Jiang Zhou ◽  
...  
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Experimental Demonstration ◽  
Proof Of Principle

Urban QKD test for phase and polarization encoding devices

2017 ◽  
Vol 15 (08) ◽  
pp. 1740018
Author(s):  
Alan Kanapin ◽  
Alexander Duplinskiy ◽  
Alexander Sokolov ◽  
Sergey Vorobey ◽  
Alexander Miller ◽  
...  
Keyword(s):  
Bit Error Rate ◽  
Quantum Key Distribution ◽  
Key Distribution ◽  
Optical Scheme ◽  
Communication Line ◽  
Key Generation ◽  
Phase Encoding ◽  
Fiber Communication ◽  
Quantum Bit ◽  
Polarization Encoding

In this work, the results of quantum key distribution through an urban fiber communication line with a length of 30.6[Formula: see text]km and losses of 11.7[Formula: see text]dB, obtained by both phase and polarization encoding-based devices, are presented. For phase encoding, a two-pass auto-compensating optical scheme, commonly called “plug&play”, was used. For polarization encoding, a self-developed unconventional optical scheme was made. A continuous key distribution with a sifted key generation rate of 1.0[Formula: see text]kbit/s and a quantum bit error rate of 5.7% was implemented when using “plug&play” device, whereas 0.1[Formula: see text]kbit/s and 5.5% was observed when using one with polarization encoding. The features and conveniences of both implementations are discussed.

scholarly journals Proof-of-principle experimental demonstration of twin-field quantum key distribution over optical channels with asymmetric losses

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Xiaoqing Zhong ◽  
Wenyuan Wang ◽  
Li Qian ◽  
Hoi-Kwong Lo
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Experimental Demonstration ◽  
Asymmetric Channel ◽  
Long Distance ◽  
Optical Channels ◽  
Fundamental Limit ◽  
Point To Point ◽  
Signal Intensities ◽  
Proof Of Principle

AbstractTwin-field (TF) quantum key distribution (QKD) is highly attractive because it can beat the fundamental limit of secret key rate for point-to-point QKD without quantum repeaters. Many theoretical and experimental studies have shown the superiority of TFQKD in long-distance communication. All previous experimental implementations of TFQKD have been done over optical channels with symmetric losses. But in reality, especially in a network setting, the distances between users and the middle node could be very different. In this paper, we perform a proof-of-principle experimental demonstration of TFQKD over optical channels with asymmetric losses. We compare two compensation strategies, that are (1) applying asymmetric signal intensities and (2) adding extra losses, and verify that strategy (1) provides much better key rate. Moreover, the higher the loss, the more key rate enhancement it can achieve. By applying asymmetric signal intensities, TFQKD with asymmetric channel losses not only surpasses the fundamental limit of key rate of point-to-point QKD for 50 dB overall loss, but also has key rate as high as 2.918 × 10−6 for 56 dB overall loss. Whereas no keys are obtained with strategy (2) for 56 dB loss. The increased key rate and enlarged distance coverage of TFQKD with asymmetric channel losses guarantee its superiority in long-distance quantum networks.

scholarly journals Robust Frame Synchronization Scheme for Continuous-Variable Quantum Key Distribution with Simple Process

Entropy ◽  
2019 ◽  
Vol 21 (12) ◽  
pp. 1146
Author(s):  
Rui Chen ◽  
Peng Huang ◽  
Dengwen Li ◽  
Yiqun Zhu ◽  
Guihua Zeng
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Continuous Variable ◽  
Quality Data ◽  
Data Synchronization ◽  
Frame Synchronization ◽  
Novel Approach ◽  
Secret Keys ◽  
Shared Secret ◽  
Synchronization Scheme

In continuous-variable quantum key distribution (CVQKD) systems, high-quality data synchronization between two legitimate parties, Alice and Bob, is the premise of the generation of shared secret keys. Synchronization with specially designed frames is an efficient way, but it requires special modulating devices to generate these special frames. Moreover, the extra requirement of special modulating devices makes it technically impossible for some passive preparation schemes. We propose a novel approach to realize synchronization in this paper, which is different from those special-frame-based methods. In our proposed scheme, Alice publishes parts of the original signals as the synchronization frames and Bob takes these frames to perform the synchronization algorithm. Besides, a synchronization feature is applied to deal with phase shifts. The simulation results based on practical data demonstrate that the proposed synchronization scheme not only maintains a high success rate but simplifies the data processing flow at the same time, which dramatically reduces the computational complexity.

EXPERIMENTAL DEMONSTRATION OF THE PERFORMANCE OF QUANTUM KEY DISTRIBUTION SYSTEM AT 1550 nm

2005 ◽  
Vol 03 (03) ◽  
pp. 561-567 ◽  
Author(s):  
YOUZHEN GUI ◽  
XIAOFAN MO ◽  
ZHENGFU HAN ◽  
GUANGCAN GUO
Keyword(s):  
Bit Error Rate ◽  
Distribution System ◽  
Quantum Key Distribution ◽  
Experimental System ◽  
Key Distribution ◽  
Experimental Demonstration ◽  
Critical Factors ◽  
Quantum Bit ◽  
Transmission Length ◽  
The Relationship

We analyze some of the critical factors that confine the transmission length for a quantum key distribution system under a certain Quantum Bit Error Rate (QBER). Emphasis was placed on the relationship between transmission length and QBER. Relationships between the minimum QBER and transmission length in theory for ideal M–Z interferometers and for the real case in theory according to the parameters of our system are given. The relationship between them as obtained by experiment was also given. The results showed that our system is very close to the performance of an ideal experimental system.

scholarly journals Device-independent quantum key distribution with random key basis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
René Schwonnek ◽  
Koon Tong Goh ◽  
Ignatius W. Primaatmaja ◽  
Ernest Y.-Z. Tan ◽  
Ramona Wolf ◽  
...  
Keyword(s):  
Quantum Key Distribution ◽  
Bell Inequality ◽  
Key Distribution ◽  
Theory And Practice ◽  
Information Theoretic ◽  
Information Theoretic Security ◽  
Experimental Parameters ◽  
Secret Keys ◽  
Simple Variant ◽  
First Time

AbstractDevice-independent quantum key distribution (DIQKD) is the art of using untrusted devices to distribute secret keys in an insecure network. It thus represents the ultimate form of cryptography, offering not only information-theoretic security against channel attacks, but also against attacks exploiting implementation loopholes. In recent years, much progress has been made towards realising the first DIQKD experiments, but current proposals are just out of reach of today’s loophole-free Bell experiments. Here, we significantly narrow the gap between the theory and practice of DIQKD with a simple variant of the original protocol based on the celebrated Clauser-Horne-Shimony-Holt (CHSH) Bell inequality. By using two randomly chosen key generating bases instead of one, we show that our protocol significantly improves over the original DIQKD protocol, enabling positive keys in the high noise regime for the first time. We also compute the finite-key security of the protocol for general attacks, showing that approximately 108–1010 measurement rounds are needed to achieve positive rates using state-of-the-art experimental parameters. Our proposed DIQKD protocol thus represents a highly promising path towards the first realisation of DIQKD in practice.

scholarly journals Experimental demonstrations of unconditional security in a purely classical regime

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Byoung S. Ham
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Unconditional Security ◽  
Zehnder Interferometer ◽  
Experimental Demonstration ◽  
Orthogonal Bases ◽  
Unitary Transformations ◽  
Mach Zehnder Interferometer

AbstractSo far, unconditional security in key distribution processes has been confined to quantum key distribution (QKD) protocols based on the no-cloning theorem of nonorthogonal bases. Recently, a completely different approach, the unconditionally secured classical key distribution (USCKD), has been proposed for unconditional security in the purely classical regime. Unlike QKD, both classical channels and orthogonal bases are key ingredients in USCKD, where unconditional security is provided by deterministic randomness via path superposition-based reversible unitary transformations in a coupled Mach–Zehnder interferometer. Here, the first experimental demonstration of the USCKD protocol is presented.

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