BT claims to have achieved a new milestone in the development of quantum-secure communications by conducting the world’s first trial of Quantum Key Distribution (QKD) over a six-kilometer-long cable of hollow core optical fiber.
QKD is a secure communication protocol that leverages security keys based on the laws of physics rather than mathematical complexity.
Explaining the significance of its trial, BT says that unlike traditional optical fiber that’s made of solid strands of glass that ferry information by channeling light signals emitted by laser transmitters, the new hollow core fiber is in fact filled with nothing but air that’s encased in a ring of glass.
BT argues that the hollow cables are better suited to the peculiarities of QKD, as it reduces the possibility of interference.
Secure quantum communication
Ferrying QKD signals is a hot topic of research. A couple of months back, Cambridge-based researchers from Toshiba shared details about their project that successfully ferried QKD signals over 600 kms.
Toshiba argued that while current commercial QKD systems are limited to about 100-200 km of fiber, its dual band stabilization technique will help preserve the signals over hundreds of kilometers.
On the other hand, BT has taken a different approach by replacing the traditional optical cables with hollow ones created by Lumenisity Limited, a spin-out from the University of Southampton.
BT argues that thanks to Lumenisity’s hollow optical cables, commercial telecommunications equipment don’t need to be optimized in order to send a data-encrypted key.
“We’ve proven a range of benefits that can be realized by deploying hollow core fiber for quantum-secure communication. Hollow core fiber’s low latency and ability to send QKD over a single fiber with other signals is a critical advancement for the future of secure communications,” noted Professor Andrew Lord, BT’s Head of Optical Network Research.