BT and Toshiba address QKD concerns with new trial

BT and Toshiba have officially launched the trial of their quantum-secured metro network which will protect the transmission of valuable data between multiple physical locations around London using quantum key distribution (QKD).

Although QKD offers “unhackable” encryption that is powerful enough to protect organisations from the rising threat of quantum cyber attacks, it’s still susceptible to man-in-the-middle (MITM) attacks, in which an exchange between two computer systems is breached by a third party.

However, Andrew Shields, head of the Quantum Technology Division at Toshiba told IT Pro that BT and Toshiba’s network is protected from man-in-the-middle attacks through quantum-safe conventional cryptography authentication:

“When the other side receives a communication, they have to know where it's coming from and that hasn't been changed in transit and we use conventional cryptography to do that authentication,” said Shields.

The cryptography is quantum-safe, meaning that it “can’t be broken by a quantum computer”, he added.

BT's managing director for applied research Tim Whitley told IT Pro that BT had been in touch with the National Cyber Security Centre (NCSC), which previously raised the concerns of potential man-in-the-middle attacks.

“They're fully aware of what we're doing in this trial and I think they’re actually very supportive of the research,” he said. The NCSC wasn’t immediately available to comment.

First announced in October 2021 and scheduled to last for three years, the trail follows a smaller-scale experiment successfully conducted last year at BT’s research and engineering campus in Adastral Park, Ipswich, where researchers used a six-metre-long hollow, air-filled cable.

This time around, the fibre ring connecting the three BT core nodes has a total length of approximately 76 km, stretching from Slough to London’s West End and City, with a trial catchment area of 20km in radial distance.

Commenting on the official launch, Minister for Science, Research and Innovation George Freeman said that the trial “represents significant progress towards achieving our ambition to make the UK a quantum-enabled economy”.

“This is the kind of innovation that helps cement the UK as a global innovation economy in the vanguard of discovering, developing and commercially adopting transformational technology with real societal benefits," he added.