QUANTUM CRYPTOGRAPHY DEVICE AND METHOD

摘要

System and method of communicating a key between two stations (1, 2) using an interferometric system for quantum cryptography. The method comprises the step of sending at least two light pulses over a quantum channel (3) and detecting the interference created by said pulses in one station (Bob). The interfering pulses run over the same arms of said interferometer, but in another sequence, so that they are delayed when they run over said quantum channel. The pulses are reflected by at least Faraday mirrors (14, 16, 22) at the ends of said quantum channel, so as to cancel polarization effects. Advantages: the system does not need alignment or balancing between the arms of the interferometers. Plug and play stations (1, 2).