Quantum cryptography takes a step forward as a continuous operation is successfully tested
The next stage of encryption could be upon us after tests of quantum cryptography had a successful operation.
The test, performed by Toshiba's Cambridge Research Lab, succeeded in demonstrating continuous operation of quantum key distribution (QKD) with a secure bit rate exceeding 1Mbps over 50km of fibre for the first time. Averaged over a 24-hour period, it claimed that this is 100-1,000 times higher than anything reported previously for a 50km link.
It said that it was achieved using two innovations developed by the Cambridge team: a novel light detector for high bit rates and a feedback system which maintains a high bit rate at all times and requires no manual set-up or adjustment.
This development could move to the roll out of ultra-secure encryption of sensitive data sent by banks, hospitals and government organisations.
Dr Andrew Shields of Toshiba Research Europe, said: “Although the feasibility of QKD with megabits per second has been shown in the lab, these experiments lasted only minutes or even seconds at a time and required manual adjustments.
“To the best of our knowledge this is the first time that continuous operation has been demonstrated at high bit rates. Although much development work remains this advance could allow unconditionally secure communication with significant bandwidths.”
Toshiba Research Europe also claimed that the breakthrough will enable the everyday use of ‘one-time pad' encryption, of which the application has been restricted in the past as it requires the transmission of very long secret keys – the same length as the data itself.
Shields claimed that for this reason, it has only been used for short messages in situations requiring very high security, but the bit rate breakthrough will extend the application of this ultra-secure communication method for everyday use.