SYSTEM AND METHOD FOR KEY DISTRIBUTION USING QUANTUM CRYPTOGRAPHY

摘要

A method of communication uses quantum cryptography to encode and decode a signal. A key is distributed on a quantum channel, and information subsequently communicated between the transmitter (1) and receiver (2) on a public channel to determine whether the key has been intercepted. A common transmission medium (3) is used for the quantum channel and public channel. A calibration signal is transmitted over the public channel on the common transmission medium to calibrate the system for the subsequent transmission of a key on the quantum channel. The transmission medium may be an optical fibre and the transmitter may switch between a single-photon output and a multiple-photon output to provide the quantum channel and public channel respectively.