Super secure data encryption gets faster

Researchers at the Cambridge Lab of Toshiba Research Europe have solved the problem of transferring highly sensitive data at high speed across a long distance network.

The team were able to demonstrate the continuous operation of quantum key distribution (QKD) -- a system that allows the communicating users to detect if a third party is trying to eavesdrop on the data communication -- at a speed greater than one megabit/sec over a 50 km fibre optic network, thanks to the use of a light detector for high bit rates and a feedback system which maintains the high bit rates during data transfer.

Having previously been able to only transfer secure data over such a distance at speeds 100 to 1,000 times slower, this development is particularly important as it could extend the real world uses for the system to hospitals, banks or anyone transmitting sensitive data.

Speaking about the research, Dr Andrew Shields -- who directed the development at 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."

Importantly, the technology will now work without user interference, and allows sensitive information to be distributed using "one-time pad" encryption -- a theoretically perfect (uh oh!) system for secure data transfer that requires the key length to be the same character length as the message, and for each encryption key (or pad) to be totally random and unique. Due to the length of the keys and slow transfer speeds one-time pad is only commonly used amongst security forces and the military to transmit short messages.

The faster one megabit/sec data handling will allow the one-time pad to be used for the encryption of video -- a vast step forward over the current ability to only encrypt voice data.

Development of the study will now extend to the National Institute of Information and Communications Technology in Tokyo where, according to Tokyo QKD network coordinator Dr. Masahide Sasaki, a quantum key distribution demonstrator will test the secure key across a wider "metropolitan network", which may ultimately lead to the technology becoming commercially available.