Key distribution method and system based on synchronized broadband physical random sources

A key distribution system based on broadband physical random sources, comprising

• a broadband physical random source and a post-processing module;
• wherein
• in the broadband physical random source, an output optical signal of a driving semiconductor laser is inputted to a first phase modulator after passing through a polarization controller;
• a driving signal of the first phase modulator is a Gaussian white noise signal generated by an arbitrary waveform generator (AWG);
• an optical signal outputted by the first phase modulator is divided into two identical paths by a fiber coupler;
• after passing through a variable optical attenuator and an optical isolator respectively, signals in the two identical paths are injected into slave semiconductor lasers at an Alice's side and a Bob's side;
• by passing output optical signals of the slave semiconductor lasers through first photodetectors and electronic amplifiers, initial synchronized signals are generated;
• the initial synchronized signals serve as driving signals of a second phase modulator at the Alice's side and a third phase modulator at the Bob's side, respectively, to phase-modulate a CW optical signal generated by a distributed feedback laser (DFB);
• output optical signals of the second phase modulator and the third phase modulator are propagated through a first dispersion module and a second dispersion module, respectively, and then inputted into second photodetectors to consequently generate synchronized broadband random signals;
• and
• in the post-processing module, final broadband synchronized signals generated by the physical random source are configured to generate synchronized high-speed keys by a post-processing method.