Quantum cryptography stretches 100 kilometres
Communications protected with the complete security of quantum cryptography are now possible over an ordinary 100-kilometre fibre optic cable, thanks to sophisticated photon detection equipment developed by UK researchers.
A team from Toshiba Research Europe, based in Cambridge, UK, has developed a quantum photon detector capable of significantly reducing the amount of random noise picked up as the super-secure cryptographic keys are generated. This boosts the fibre optic distance over which quantum cryptography is feasible.
Quantum cryptography guarantees secure communications by harnessing the quantum quirks of photons sent between users. Any attempt to intercept the photons will disturb their quantum state and, because this quantum quality is an integral part of key generation, the disturbance with immediately raise the alarm.
But reducing the amount of random noise picked up by a detector at either end of a fibre link is crucial. If the noise level is too high, the key generation process will fail too many times to be practical. Until now, no device has been able to make it work across such a long optical link.
[ Read more ]
- Article: Quantum Cryptography (4 April 2002)
By subscribing to our early morning news update, you will receive a daily digest of the latest security news published on Help Net Security.
With over 500 issues so far, reading our newsletter every Monday morning will keep you up-to-date with security risks out there.