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arXiv:2006.06166 · Physical Review Applied

Trusted Detector Noise Analysis for Discrete Modulation Schemes of Continuous-Variable Quantum Key Distribution

Jie Lin, Norbert Lütkenhaus

Published Dec 9, 2020• 50 citations
arXivHTMLPDF

Abstract

Discrete-modulated continuous-variable quantum key distribution protocols are promising candidates for large-scale deployment due to the large technological overlap with deployed modern optical communication devices. The security of discrete modulation schemes has previously been analyzed in the ideal detector scenario in the asymptotic limit. In this work, we calculate asymptotic key rates against collective attacks in the trusted detector noise scenario. Our results show that we can thus cut out most of the effect of detector noise and obtain asymptotic key rates similar to those had we access to ideal detectors.

DOI
10.1103/physrevapplied.14.064030

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The system's source noise affects the practical performance of discrete-modulated continuous-variable quantum key distribution. The good news: This noise exists inside the system and cannot be exploited by eavesdroppers, so it can be trusted. However, a lack of appropriate modeling leaves a security-key-rate gap, omitting this trusted noise. The authors propose a model for trusted source noise in the discrete-modulated protocol, successfully mitigating the negative impact of an imperfect source on system performance while maintaining security of the protocol, and thus promoting practical deployment.