The UK’s first quantum network was launched last month in Cambridge, enabling ‘unhackable’ communications between three sites — the Electrical Engineering Division in West Cambridge, the Department of Engineering in the city centre and Toshiba Research Europe Ltd (TREL) on the Cambridge Science Park.

The systemis secure because it uses particles of light (photons) to transmit encryption keys via the optical fibre.

If an attempt is made to intercept the communication, the key itself changes through the laws of quantum mechanics, rendering the stolen data useless.

Researchers have been testing the ultra-secure network for the last year, providing stable generation of quantum keys at rates between two and three megabits per second. These keys are used to securely encrypt data, both in transit and in storage.

The Cambridge network is a project of the Quantum Communications Hub (QCH), a consortium of eight UK universities plus private-sector companies and public-sector stakeholders.

The network was built by Hub partners including the university’s Electrical Engineering Division and TREL, which also supplied the Quantum Key Distribution (QKD) systems.

Further input came from ADVA, which supplied the optical transmission equipment, and the university’s Granta Backbone Network, which provided the optical fibre.

QCH director Timothy Spiller said: “Through this network, we can further improve quantum communications technologies and interoperability, explore and develop applications and services, and also demonstrate these to potential end users and future customers.”

The UK Quantum Network is funded by the Engineering and Physical Sciences Research Council (EPSRC). Liam Blackwell, head of quantum technologies at EPSRC, said: “Development of the network has brought together many world-class researchers and facilities from both UK universities and industry.

“This is a reflection of EPSRC’s commitment to investing in UK leadership in advanced research and innovation in quantum technologies.”