scholarly journals Full daylight quantum-key-distribution at 1550 nm enabled by integrated silicon photonics

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
M. Avesani ◽  
L. Calderaro ◽  
M. Schiavon ◽  
A. Stanco ◽  
C. Agnesi ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Silicon Photonics ◽  
Free Space ◽  
Quantum Key Distribution ◽  
Cost Effective ◽  
Key Distribution ◽  
Global Scale ◽  
Secret Key ◽  
Quantum Bit ◽  
Integrated Silicon Photonics

AbstractThe future envisaged global-scale quantum-communication network will comprise various nodes interconnected via optical fibers or free-space channels, depending on the link distance. The free-space segment of such a network should guarantee certain key requirements, such as daytime operation and the compatibility with the complementary telecom-based fiber infrastructure. In addition, space-to-ground links will require the capability of designing light and compact quantum devices to be placed in orbit. For these reasons, investigating available solutions matching all the above requirements is still necessary. Here we present a full prototype for daylight quantum key distribution at 1550 nm exploiting an integrated silicon-photonics chip as state encoder. We tested our prototype in the urban area of Padua (Italy) over a 145 m-long free-space link, obtaining a quantum bit error rate around 0.5% and an averaged secret key rate of 30 kbps during a whole sunny day (from 11:00 to 20:00). The developed chip represents a cost-effective solution for portable free-space transmitters and a promising resource to design quantum optical payloads for future satellite missions.

HỆ THỐNG PHÂN PHỐI KHÓA LƯỢNG TỬ ĐA KÊNH TỪ VỆ TINH SỬ DỤNG SCM-WDM

2021 ◽  
pp. 35-43
Author(s):  
Hiền
Keyword(s):  
Wavelength Division Multiplexing ◽  
Bit Error Rate ◽  
Error Rate ◽  
Free Space ◽  
Quantum Key Distribution ◽  
Key Distribution ◽  
Secret Key ◽  
Quantum Bit ◽  
Wavelength Division ◽  
Free Space Optic

Phân phối khoá lượng tử QKD (Quantum Key Distribution) là giải pháp có khả năng đảm an ninh vô điều kiện nhờ áp dụng luật cơ lượng tử để phân phối khóa an toàn giữa hai bên hợp pháp với sự hiện diện của kẻ nghe lén. Sử dụng vệ tinh để phân phối khóa lượng tử tới các trạm mặt đất qua kênh quang không gian tự do FSO (Free Space Optic) là giải pháp hứa hẹn tạo ra một mạng QKD phạm vi toàn cầu. Tuy nhiên, do ảnh hưởng của kênh FSO, đặc biệt là nhiễu loạn khí quyển, tốc độ truyền khóa bí mật SKR (Secret Key Rate) của các hệ thống QKD hiện tại bị hạn chế. Do đó, nghiên cứu này đề xuất mô hình hệ thống QKD đa kênh dựa trên ghép kênh phân chia theo bước sóng WDM (Wavelength Division Multiplexing) và ghép kênh sóng mang phụ SCM (Sub Carrier Multiplexing) nhằm tăng SKR. Sử dụng phương pháp phân tích lý thuyết với các công cụ giải tích và xác suất, nhóm tác giả đã xây dựng các công thức tính toán SKR và tỉ lệ lỗi bit lượng tử của hệ thống đề xuất. Kết quả khảo sát hiệu năng cho thấy, hệ thống QKD đa kênh cho phép cải thiện SKR so với hệ thống đơn kênh trong khi vẫn đảm bảo yêu cầu về QBER (Quantum Bit Error Rate).

scholarly journals Geometrical Optics Restricted Eavesdropping Analysis of Satellite-to-Satellite Secret Key Distillation

Entropy ◽  
2021 ◽  
Vol 23 (8) ◽  
pp. 950
Author(s):  
Ziwen Pan ◽  
Ivan B. Djordjevic
Keyword(s):  
Free Space ◽  
Quantum Key Distribution ◽  
Security Analysis ◽  
Key Distribution ◽  
Geometrical Optics ◽  
Secret Key ◽  
Satellite Applications

Traditionally, the study of quantum key distribution (QKD) assumes an omnipotent eavesdropper that is only limited by the laws of physics. However, this is not the case for specific application scenarios such as the QKD over a free-space link. In this invited paper, we introduce the geometrical optics restricted eavesdropping model for secret key distillation security analysis and apply to a few scenarios common in satellite-to-satellite applications.

An Efficient Reconciliation in Removing Errors Using Bose, Chaudhuri, Hocquenghem Code for Quantum Key Distribution

2012 ◽  
pp. 13-19
Author(s):  
Riaz Ahmad Qamar ◽  
Mohd Aizaini Maarof ◽  
Subariah Ibrahim
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Quantum Key Distribution ◽  
Error Probability ◽  
Key Distribution ◽  
Secret Key ◽  
Post Processing ◽  
Quantum Bit ◽  
Quantum Bit Error Rate ◽  
Quantum Key Distribution Protocol

A quantum key distribution protocol(QKD), known as BB84, was developed in 1984 by Charles Bennett and Gilles Brassard. The protocol works in two phases which are quantum state transmission and conventional post processing. In the first phase of BB84, raw key elements are distributed between two legitimate users by sending encoded photons through quantum channel whilst in the second phase, a common secret-key is obtained from correlated raw key elements by exchanging messages through a public channel e.g.; network or internet. The secret-key so obtained is used for cryptography purpose. Reconciliation is a compulsory part of post processing and hence of quantum key distribution protocol. The performance of a reconciliation protocol depends on the generation rate of common secret-key, number of bits disclosed and the error probability in common secrete-key. These characteristics of a protocol can be achieved by using a less interactive reconciliation protocol which can handle a higher initial quantum bit error rate (QBER). In this paper, we use a simple Bose, Chaudhuri, Hocquenghem (BCH) error correction algorithm with simplified syndrome table to achieve an efficient reconciliation protocol which can handle a higher quantum bit error rate and outputs a common key with zero error probability. The proposed protocol efficient in removing errors such that it can remove all errors even if QBER is 60%. Assuming the post processing channel is an authenticated binary symmetric channel (BSC).

scholarly journals Security of quantum key distribution with state-dependent imperfections

2011 ◽  
Vol 11 (11&12) ◽  
pp. 937-947
Author(s):  
Hong-Wei Li ◽  
Zhen-Qiang Yin ◽  
Shuang Wang ◽  
Wan-Su Bao ◽  
Guang-Can Guo ◽  
...  
Keyword(s):  
Error Rate ◽  
Distribution System ◽  
Quantum Channel ◽  
Quantum Key Distribution ◽  
Phase Error ◽  
Key Distribution ◽  
The State ◽  
Secret Key ◽  
Quantum Bit ◽  
State Dependent

In practical quantum key distribution system, the state preparation and measurement have state-dependent imperfections comparing with the ideal BB84 protocol. If the state-dependent imperfection can not be regarded as an unitary transformation, it should not be considered as part of quantum channel noise introduced by the eavesdropper, the commonly used secret key rate formula GLLP can not be applied correspondingly. In this paper, the unconditional security of quantum key distribution with state-dependent imperfections will be analyzed by estimating upper bound of the phase error rate in the quantum channel and the imperfect measurement. Interestingly, since Eve can not control all phase error in the quantum key distribution system, the final secret key rate under constant quantum bit error rate can be improved comparing with the perfect quantum key distribution protocol.

scholarly journals Integrated silicon photonics for high-speed quantum key distribution

Optica ◽  
2017 ◽  
Vol 4 (2) ◽  
pp. 172 ◽  
Author(s):  
Philip Sibson ◽  
Jake E. Kennard ◽  
Stasja Stanisic ◽  
Chris Erven ◽  
Jeremy L. O’Brien ◽  
...  
Keyword(s):  
Silicon Photonics ◽  
Quantum Key Distribution ◽  
High Speed ◽  
Key Distribution ◽  
Integrated Silicon Photonics

scholarly journals Modeling and Simulation for Performance Evaluation of Optical Quantum Channels in Quantum key Distribution Systems

2021 ◽  
Vol 17 (2) ◽  
pp. 31-44
Author(s):  
Adil Fadhil Mushatet ◽  
Shelan Khasro Tawfeeq
Keyword(s):  
Performance Evaluation ◽  
Optical Fiber ◽  
Free Space ◽  
Quantum Channel ◽  
Quantum Key Distribution ◽  
Distribution Systems ◽  
Key Distribution ◽  
Quantum Channels ◽  
Quantum Bit ◽  
Modeling Process

In this research work, a simulator with time-domain visualizers and configurable parameters using a continuous time simulation approach with Matlab R2019a is presented for modeling and investigating the performance of optical fiber and free-space quantum channels as a part of a generic quantum key distribution system simulator. The modeled optical fiber quantum channel is characterized with a maximum allowable distance of 150 km with 0.2 dB/km at =1550nm. While, at =900nm and =830nm the attenuation values are 2 dB/km and 3 dB/km respectively. The modeled free space quantum channel is characterized at 0.1 dB/km at =860 nm with maximum allowable distance of 150 km also. The simulator was investigated in terms of the execution of the BB84 protocol based on polarizing encoding with consideration of the optical fiber and free-space quantum channel imperfections and losses by estimating the quantum bit error rate and final secure key. This work shows a general repeatable modeling process for significant performance evaluation. The most remarkable result that emerged from the simulated data generated and detected is that the modeling process provides guidance for optical quantum channels design and characterization for other quantum key distribution protocols.

Optimized decoy state QKD for underwater free space communication

2018 ◽  
Vol 16 (02) ◽  
pp. 1850019 ◽  
Author(s):  
Minal Lopes ◽  
Nisha Sarwade
Keyword(s):  
Free Space ◽  
Key Distribution ◽  
Communication Model ◽  
Secret Key ◽  
Space Communication ◽  
Decoy State ◽  
Quantum Bit ◽  
Enhanced Transmission ◽  
Transmission Distance ◽  
Free Space Communication

Quantum cryptography (QC) is envisioned as a solution for global key distribution through fiber optic, free space and underwater optical communication due to its unconditional security. In view of this, this paper investigates underwater free space quantum key distribution (QKD) model for enhanced transmission distance, secret key rates and security. It is reported that secure underwater free space QKD is feasible in the clearest ocean water with the sifted key rates up to 207[Formula: see text]kbps. This paper extends this work by testing performance of optimized decoy state QKD protocol with underwater free space communication model. The attenuation of photons, quantum bit error rate and the sifted key generation rate of underwater quantum communication is obtained with vector radiative transfer theory and Monte Carlo method. It is observed from the simulations that optimized decoy state QKD evidently enhances the underwater secret key transmission distance as well as secret key rates.

Performance of reference-frame-independent quantum key distribution in underwater channel

2021 ◽  
pp. 2150011
Author(s):  
Zhongqi Sun ◽  
Jipeng Wang ◽  
Zhenhua Li ◽  
Wenxiu Qu ◽  
Tianqi Dou ◽  
...  
Keyword(s):  
Reference Frame ◽  
Experimental Research ◽  
Free Space ◽  
Quantum Key Distribution ◽  
Channel Model ◽  
Key Distribution ◽  
Secret Key ◽  
Optical Attenuation ◽  
Simulation Results

During free-space quantum key distribution, the rotation and fluctuation of reference frame degrades the performance of quantum key distribution (QKD). Reference-frame-independent QKD (RFI-QKD) overcomes this issue effectively. To date, much theoretical and experimental research has been conducted on the performance of free-space RFI-QKD. However, these studies are all based on free-space air and satellite ground, and none have investigated the performance of RFI-QKD in an underwater channel. Therefore, this paper constructed a channel model that considered both scattering and optical attenuation to obtain an RFI-QKD secret key rate in an underwater channel. The simulation results confirm that even in a relatively harsh underwater scenario, RFI-QKD maintains good performance.

Twin-field quantum key distribution over free-space optical channels in the presence of atmospheric turbulence

2022 ◽  
Author(s):  
Yuqing Huang ◽  
Zhongqi Sun ◽  
Tianqi Dou ◽  
Jipeng Wang ◽  
Zhenhua Li ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Communication Networks ◽  
Free Space ◽  
Quantum Key Distribution ◽  
Quantum Communication ◽  
Channel Model ◽  
Key Distribution ◽  
Global Scale ◽  
Free Space Optical ◽  
Optical Channels

Future quantum communication networks envisaged on a global scale will include various networks interlinked via optical fiber and free space channels. In recent years, quantum key distribution (QKD) protocol based on optical fiber has been extensively studied. Twin-field QKD (TF-QKD) may enable 550 km QKD using standard optical fiber without quantum repeaters. However, the performance of TF-QKD in free-space channel is still unclear. In this paper, a free-space channel model is proposed with specific turbulence characterization discussed. Here, the key rate of TF-QKD under multiple scenarios considering the variation of turbulence and different link configuration is investigated. Simulation results demonstrate that the performance of free-space TF-QKD is related to link configuration and turbulence motion which is determined by surface feature, time and height. Furthermore, TF-QKD protocol is a potential scheme for the free-space quantum communication.

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