Enhancing cybersecurity against future threats is crucial, especially with the emergence of quantum computers that could potentially compromise existing encryption methods. Quantum communications offer unparalleled security measures to combat these risks.
Researchers worldwide have made significant strides in developing quantum networks to bolster security measures. For instance, China has established a 4,600-kilometer network connecting cities via fiber optics and satellites. In Madrid, a smaller network with nine nodes securely shares data using various Quantum Key Distribution (QKD) techniques. Additionally, record-breaking key rates were achieved in Cambridge and Toshiba in 2019, while Bristol successfully enabled entanglement sharing in 2020. Similar trials have taken place in Singapore, Italy, and the USA.
Despite these advancements, a comprehensive network combining Quantum Key Distribution (QKD), entanglement, and standard data transmission had not been achieved until now.
A breakthrough was made by a collaborative team from the Universities of Bristol and Cambridge, who successfully demonstrated the UK’s first long-distance quantum-secured video call and ultra-secure data transfer over a quantum communications network. This network spans over 410 kilometers of fiber optic infrastructure between Bristol and Cambridge, utilizing two QKD schemes: encryption keys embedded in light particles and distributed entanglement, where quantum particles remain interconnected.
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The demonstration showcased the network’s capabilities through a quantum-secure video call, encrypted medical data transfer, and remote access to a distributed data center. This achievement signifies the successful integration of long-distance quantum-secured technologies, such as entanglement distribution and regular data transmission.
The experiment highlights:
- The potential of quantum networks to integrate various quantum-secure approaches alongside traditional communication infrastructure.
- The utilization of the UK’s Quantum Network (UKQN), developed over the past decade with support from the Engineering and Physical Sciences Research Council (EPSRC) and the Quantum Communications Hub project.
- The incorporation of multiple quantum communication technologies, including secure key management systems for seamless encryption.
- A significant advancement in providing quantum security on a national scale, paving the way for a future quantum internet connecting nodes and devices through entanglement and teleportation.
- Highlighting the UK’s expertise in quantum networking technology and setting the stage for resilient communication systems in the future.
The team’s future endeavors include the continuation of their work through a new EPSRC-funded project, the Integrated Quantum Networks Hub. This project aims to develop quantum networks of all scales, from local quantum processors’ connection to the establishment of national and intercontinental networks using low-earth orbit satellites for secure communication, computing, and sensing.
Journal Reference:
- R. Yang et al. A UK nationwide heterogeneous quantum network. Presented at the 2025 Optical Fiber Communications Conference and Exhibition (OFC)