Quantum cryptography, a completely secure means of communication, is much closer to being used practically. Researchers from the Toshiba company and Cambridge University’s Cavendish Laboratory have now developed high speed detectors capable of receiving information with much higher key rates, allowing more information to be received faster.
Published as part of IOP Publishing’s New Journal of Physics’ Focus Issue on Quantum Cryptography: Theory and Practice, the paper details how quantum communication can be made possible without having to use cryogenic cooling and/or complicated optical setups, thus making the technology much more likely to become commercially viable soon. One of the first practical applications to emerge from advances in the study of quantum mechanics, quantum cryptography has become the soon-to-be-reached gold standard in secure communications. Quantum cryptography uses the quantum mechanical behaviour of photons to enable highly secure transmission of data beyond that achievable by classical encryption. The photons themselves are used to distribute keys that enable access to encrypted information, such as a video file that a bank wishes to keep completely confidential, which can be sent along practical communication lines made of fibre optics. Quantum indeterminacy, the quantum mechanics dictum which states that measuring an unknown quantum state will change it, means that the key information cannot be accessed by a third party without corrupting it beyond recovery and therefore making the act of hacking futile.
While other detectors can offer a key rate close to that reported in this paper, the present advance only relies on practical components for high speed photon detection, which has previously required either cryogenic cooling or highly technical optical setups, to make quantum key distribution much more user-friendly.Using an attenuated laser as a light source and a compact detector (semiconductor avalanche photodiodes), the researchers have introduced a decoy protocol to guard against intruder attacks that would confuse with erroneous information all but the sophisticated, compact detector developed by the researchers.
www.opticsinfobase.org/oe/abstract.cfm
