DFTs-OFDM based quantum noise stream cipher system

Abstract

Abstract Quantum noise stream cipher (QNSC) is a physical layer encryption technique based on quantum noise. Discrete-fourier-transform spread orthogonal frequency division multiplexing (DFTs-OFDM) is a widely studied technology with excellent transmission performance. As best as we know, the transmission and security performance of QNSC in DFTs-OFDM transmission has not been studied. This paper introduces DFTs-OFDM into the QNSC system to combine the characteristics of both techniques. Simulation results show that PSK-based QNSC (PSK/QNSC) has better transmission and security performance than QAM-based QNSC (QAM/QNSC) under the same constellation size. As the constellation size increases, obtained security can be upgraded. We also investigate the effects of quantization and clipping noise on the performance of DFTs-OFDM based QAM/QNSC system. We experimentally demonstrate a 10-Gbit/s DFTs-OFDM based PSK/QNSC and QAM/QNSC transmission over a single span 200-km fiber link.