Efficient Quantum Key Distribution

高效的量子密钥分发

• 批准号: 2625739
• 金额: --
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2625739
• 关键词: Efficient; Quantum; Key; Distribution

Research questionCoherent communication with quadrature modulated light is a well-developed communication scheme for conventional 100G internet traffic. But, at extremely low signal strength, inherent quantum features of light such as vacuum noise dominate and prevent the exchange of meaningful messages. However, it is possible to harness and exploit this quantum uncertainty to make it useful for secure key distribution. Continuous Variable Quantum Key Distribution (CV-QKD) is such a quantum technology which is also highly efficient for deployment in DWDM networks such that quantum and conventional channels can co-exist.CV-QKD Local Local Oscillator (LLO) schemes that converge to coherent communication have recently been gaining interest. They open up an excellent opportunity for testing and evaluating the performance of coherent communication techniques for distributing quantum signals. However, recent demonstrations of these approaches have been limited to low loss channels with reduced key rates, due to elevated receiver noise.Approach/MethodologyThis project aims to develop new CV-QKD LLO schemes for high channel loss applications with enhanced secure key rates. One direction of this work will be to recover the quantum signal information from a noisy coherent receiver. Within this project, the student will work on measurement of the quantum channel at very low receiver noise to demonstrate the potential for high performance operation. Noise reduction and optimization of CV-QKD parameters will be the major consideration for this development. This study will be extended to multi transmitter or multidimensional quantum signal detection to enhance the secure key bandwidth.The work on the link will initially focus on measuring the noise and then extrapolating to the possible secure key rate under various quantum attacks. However, once this initial phase is complete the student will then work on a link that distils a real secure key that can be used to encode conventional channels on the existing Cambridge quantum network. Later in this project, the feasibility of extended to a national scale using the National Dark Fibre Facility will be investigated. This research is primarily experimental, using the Cambridge CV-QKD system, but moderate theoretical study is also necessary. It will be linked to the major EPSRC Quantum Technology Hub, QComm2.

正交调制光相干通信是一种成熟的传统100G网络通信方案。但是，在极低的信号强度下，光的固有量子特征（如真空噪声）占主导地位，阻碍了有意义信息的交换。然而，可以利用这种量子不确定性使其对安全密钥分发有用。连续可变量子密钥分发（CV-QKD）就是这样一种量子技术，它也可以高效地部署在DWDM网络中，使量子信道和传统信道并存。CV-QKD局部本振（LLO）方案收敛于相干通信，近年来引起了人们的兴趣。它们为测试和评估用于分配量子信号的相干通信技术的性能提供了一个极好的机会。然而，由于接收器噪声升高，这些方法的最近演示仅限于低损耗信道和降低的密钥速率。方法/方法本项目旨在开发新的CV-QKD LLO方案，用于高信道损耗应用，提高安全密钥速率。从有噪声的相干接收机中恢复量子信号信息将是这项工作的一个方向。在这个项目中，学生将在非常低的接收器噪声下测量量子信道，以展示高性能操作的潜力。降噪和优化CV-QKD参数将是这一发展的主要考虑因素。该研究将扩展到多发射机或多维量子信号检测，以提高安全密钥带宽。链路上的工作将首先集中于测量噪声，然后推断出在各种量子攻击下可能的安全密钥速率。然而，一旦这个初始阶段完成，学生们就会在一个链路上工作，提炼出一个真正的安全密钥，可以用来对现有剑桥量子网络上的传统信道进行编码。在这个项目的后期，将研究使用国家暗纤维设施扩展到国家规模的可行性。本研究以实验为主，采用Cambridge CV-QKD系统，但也有必要进行适度的理论研究。它将连接到主要的EPSRC量子技术中心QComm2。