Japanese boffins have succeeded in achieving whats touted as the Worlds fastest continuous quantum cryptography key generation. Researchers from NEC, the National Institute of Information and Communications Technology and the Japan Science and Technology Agency achieved a fortnight-long, continuous quantum cryptography final-key generation at an average rate of 13kbps over a 16-km-long commercial optical network.
Quantum cryptography allows two users on an optical fibre network to exchange secret keys. It takes advantage of the particle-like nature of light. In quantum cryptography, each bit of the key is encoded upon a single light particle (or "photon" ). Intercepting this data randomly changes the polarisation of the light, irreversibly altering the data. Because of this quantum mechanics effect any attempt by an eavesdropper to determine a key corrupts the same key. Quantum cryptography systems discard these corrupt keys and only use codes that are known to be secure. These quantum keys, once exchanged, can be used in a one-time pad.
News source: The Register