Cryptographic protection of sensitive information is arguably facing its most severe challenge to date thanks to quantum computers. To counter this threat, researchers around the globe are investigating new ways to protect secret keys used to send and unlock encrypted data. One advanced method close to commercialization is quantum key distribution (QKD).

QKD employs a feature of quantum mechanics known as the uncertainty principle to ensure transmitted key data cannot be interfered with by an outside party without irreversibly altering the data. Any interference will leave its mark and be detected by the sender and receiver.

Toshiba is leading in high-speed QKD and has been holding field trials in Japan and the UK for several years. Recently, Toshiba and Tohoku Medical Megabank Organization (ToMMo) at Tohoku University announced that they have achieved, for the first time, an average key distribution speed greater than 10 megabits per second (Mbps) over a one-month period. This is roughly five times faster than the previous fastest QKD speed of 1.9 Mbps established by Toshiba Research Europe in 2016.