Network-type QKD system
Google unveiled a novel quantum error-correction architecture alongside a superconducting quantum processor, making a pivotal advance toward the practical realization of quantum computational advantage. These developments also underscore the escalating cybersecurity threats posed by emerging quantum technologies. Consequently, countries worldwide are actively developing quantum key distribution (QKD), which relies on fundamental physical principles for security, thereby safeguarding systems against the potential threats posed by quantum computing. We constructed a multi-user, scalable quantum network prototype based on the MDIQKD architecture. This protocol requires a central measurement node that simultaneously connects multiple end users to enable secure key distribution and sharing. Through this star-shaped configuration, we demonstrated a key distribution system supporting three users, with not only the capability to flexible expand the number of participants, but also effectively prevents potential eavesdroppers from exploiting side-channel attacks. We applied our network-based QKD system in a real-world setting to achieve absolutely secure communication network.