Quantum key distribution (QKD) networks are promising to serve large numbers of users with information-theoretic secure communication. In QKD networks, the detection-safe protocol, termed measurement-device-independent (MDI) QKD, can naturally enhance realistic security by supporting untrusted measurement nodes. However, the environmental disturbances to quantum states degrade the performance of multi-user communication. Here we propose an MDI-QKD networking scheme with robustness against environmental disturbance and adaptability to multi-user access, where more than two users can generate keys simultaneously regardless of aligning reference frames and compensating channel disturbance on polarization. To achieve this, we introduce the reference-frame-independent protocol as well as a polarization-compensation-free method, design a multi-user measurement unit, and combine it with original two-user units. The scheme is experimentally demonstrated for the improvement of network robustness and adaptability in multi-user scenarios, and the time and device costs of disturbance compensation can be saved from O(N)$O(N)$ to O(1)$O(1)$ for an N-user network.

中文翻译：

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没有可信节点的健壮且适应性强的量子密钥分发网络

量子密钥分发 (QKD) 网络有望通过信息论安全通信为大量用户提供服务。在 QKD 网络中，被称为独立于测量设备 (MDI) QKD 的检测安全协议可以通过支持不受信任的测量节点来自然地增强现实安全性。然而，环境对量子态的干扰会降低多用户通信的性能。在这里，我们提出了一种 MDI-QKD 网络方案，该方案具有对环境干扰的鲁棒性和对多用户访问的适应性，其中两个以上的用户可以同时生成密钥，而不管对齐参考帧和补偿极化上的信道干扰。为此，我们引入了与参考帧无关的协议以及无偏振补偿的方法，设计一个多用户测量单元，并与原有的二用户单元结合。该方案为提高网络在多用户场景下的鲁棒性和适应性进行了实验验证，可以节省干扰补偿的时间和设备成本。$O(N)$对于 N 用户网络， O(N)到O(1) 。$O(1)$