Quantum key distribution (QKD) networks constitute promising solutions for secure communication. Beyond conventional point-to-point QKD, we developed 1 × N QKD network systems with a sub-nanosecond resolution optical path length compensation scheme. With a practical plug-and-play QKD architecture and compact timing control modules based on a field-programmable gate array, we achieved long-term stable operation of a 1×64 QKD network system. Using this architecture, 64 users can simultaneously share secret keys with one server, without using complex software algorithms and expensive hardware. We demonstrated the workings of a 1×4 QKD network system using the fiber network of a metropolitan area.

中文翻译：

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用于1×N量子密钥分发网络系统的具有亚纳秒时间分辨率的用户无关光路长度补偿方案

量子密钥分发 (QKD) 网络构成了安全通信的有前途的解决方案。除了传统的点对点 QKD，我们还开发了具有亚纳秒分辨率光路长度补偿方案的 1 × N QKD 网络系统。通过实用的即插即用 QKD 架构和基于现场可编程门阵列的紧凑型时序控制模块，我们实现了 1×64 QKD 网络系统的长期稳定运行。使用这种架构，64 个用户可以同时与一台服务器共享密钥，而无需使用复杂的软件算法和昂贵的硬件。我们使用城域光纤网络演示了 1×4 QKD 网络系统的工作原理。