Current quantum key distribution (QKD) networks focus almost exclusively on transporting secret keys at the highest possible rate. Consequently, they are built as mostly fixed, ad hoc, logically, and physically isolated infrastructures designed to avoid any penalty to the quantum channel. This architecture is neither scalable nor cost-effective and future, real-world deployments will differ considerably. The structure of the MadQCI QKD network presented here is based on disaggregated components and modern paradigms especially designed for flexibility, upgradability, and facilitating the integration of QKD in the security and telecommunications-networks ecosystem. These underlying ideas have been tested by deploying many QKD systems from several manufacturers in a real-world, multi-tenant telecommunications network, installed in production facilities and sharing the infrastructure with commercial traffic. Different technologies have been used in different links to address the variety of situations and needs that arise in real networks, exploring a wide range of possibilities. Finally, a set of realistic use cases has been implemented to demonstrate the validity and performance of the network. The testing took place during a period close to three years, where most of the nodes were continuously active.

当前的量子密钥分发（QKD）网络几乎完全专注于以尽可能高的速率传输秘密密钥。因此，它们大多被构建为固定的、临时的、逻辑上和物理上隔离的基础设施，旨在避免对量子通道造成任何影响。这种架构既不具有可扩展性，也不具有成本效益，并且未来的实际部署将存在很大差异。这里介绍的 MadQCI QKD 网络的结构基于分类组件和现代范例，专为灵活性、可升级性以及促进 QKD 在安全和电信网络生态系统中的集成而设计。这些基本想法已经通过在现实世界的多租户电信网络中部署来自多家制造商的许多 QKD 系统进行了测试，这些系统安装在生产设施中并与商业流量共享基础设施。不同的技术被运用在不同的环节，解决现实网络中出现的各种情况和需求，探索多种可能性。最后，实施了一组实际用例来证明网络的有效性和性能。测试进行了近三年，其中大多数节点持续活跃。