A Novel Realization of PSK Quantum-noise Randomized Cipher System Based on Series Structure of Multiple Phase Modulators

Quantum-Noise Randomized Cipher (QNRC) is a potentially information-theoretic secure physical-layer encryption method for high-speed and long-distance fiber communications. In order to solve the problem that the modulation and demodulation of M-ary Y-00 ciphertext signal in QNRC system are limited by the ADC chip with high sampling rate and high conversion depth, a novel realization of PSK-QNRC system based on series structure of multiple phase modulators (PM) is proposed, and the performances of the proposed scheme is verified by using commercial simulation software in this paper. The simulation results show that, the 126-PSK QNRC system at 10 Gbit/s over 1000-km optically amplified links is realized based on the series structure of multiple PM. Reducing the mesoscopic power of the ciphertext quantum state can improve the security level of QNRC system, but it will damage the transmission performance of the system at the same time. It is very important to select the appropriate mesoscopic power to optimize the security and reliability of QNRC system.