Physical-layer security analysis of a quantum noise randomized cipher assisted by chaos masking

Abstract

By applying intensity modulation, the quantum noise random cipher (QNRC) hides the signal amplitude in quantum noise to prevent eavesdropping. It is an essential topic for evaluating the secret performance of the QNRC system. In this paper, the physical-layer security of the QNRC based on intensity modulation (IM-QNRC) with chaos masking (CMA) is quantitatively analysed. The model of the transmission system is built. Additionally, the noise-mask-signal number (NMN) and the probability of correctly guessing data for the interceptor (PCG) are used as metrics to assess the security of the physical layer. The general expression of PCG for an eavesdropper is derived. A comprehensive evaluation and comparison of the security metrics versus several system parameters are carried out. Based on simulation, the mixing of chaos masking reduces the PCG of the QNRC system with suitable parameters by approximately 8 orders of magnitude. The QNRC system combined with CMA can realize higher anti-interception communication.