Security analysis of continuous-variable quantum key distribution with imperfect Faraday mirror. (17th October 2019)

• Record Type: Journal Article
• Authors: Liang, Kexin; Cao, Zhengwen; Liu, Weiqi; Wang, Jiayao; Chai, Geng; Zhang, Tongyi
• Is Part Of: Laser physics letters. Volume 16:Number 11(2019:Nov.)
• Publication Date: 2019-10-17
• Subjects: continuous variable -- quantum key distribution (QKD) -- Faraday mirror (FM); Lasers -- Periodicals; Physics -- Periodicals; 621.366
• DOI: 10.1088/1612-202X/ab4995
• Languages: English
• ISSNs: 1612-2011

Abstract

Abstract: For the practical Faraday mirror (FM) in a continuous-variable quantum key distribution (CVQKD) system there exists a rotation angle deviation that can lead to a loss of photon number when a light message passes through the polarization beam splitter. Here we employ the entanglement-based model to research the influence of the FM's imperfection. Based on parameter estimation, the imperfection can introduce a loophole for Eve to obtain information. The secret key rate of the CVQKD will be impaired. Finally, a novel method is proposed to ensure system performance by compensating optical power, and we further study the relationship between the secret key rate and the modulation variance.