BT has partnered with Toshiba to build and trial the world’s first quantum-secured metro network. The network will connect sites in London’s Docklands, the City and the M4 Corridor, and will provide data services secured using Quantum Key Distribution (QKD) and Post-Quantum Cryptography (PQC).

This is the world’s first commercial trial of a quantum network infrastructure. It will be operated by BT, who will provide a range of quantum-secured services including dedicated high bandwidth end-to-end encrypted links, delivered over Openreach’s Optical Spectrum Access Filter Connect (OSA FC) solution for private fibre networks.

BT said the QKD links will be provided using a quantum network that includes both core and access components, and will be integrated into BT’s existing network management operations. Toshiba will provide quantum key distribution hardware and key management software.

While BT and Toshiba have previously installed a point-to-point quantum-secure link between two commercial sites, deploying a full quantum-secured metro network environment with multiple endpoints requires new approaches to integration and management.

Toshiba launched commercial products for QKD, manufactured at its Cambridge site, in the latter half of 2020. These offer the highest key rates (1,000’s of keys per second) and longest range of any commercially available fibre QKD system.

Toshiba’s innovative multiplexing compatibility allows the data and the quantum keys to be transmitted on the same fibre, eliminating the need for costly dedicated infrastructure for key distribution. Toshiba will also supply network key delivery and management software that enables end-to-end protection of data across the network.

Howard Watson, CTO of BT, said: “BT and Toshiba have established a global lead in the development of quantum-secure networks. We’re excited to be taking this collaboration to the next level by building the world’s first commercially operational quantum-secured metro network in London.”

Taro Shimada, Chief Digital Officer at Toshiba, said: “Our partnership with BT will allow us to offer organisations quantum-secured network services which protect their data from retrospective attacks with a quantum computer.”