Practical continuous-variable quantum key distribution using dynamic digital signal processing: security proof and experimental demonstration
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Quantum Physics arXiv:2602.05206 (quant-ph) [Submitted on 5 Feb 2026] Title:Practical continuous-variable quantum key distribution using dynamic digital signal processing: security proof and experimental demonstration Authors:Lu Fan, Zhengyu Li, Sheng Liu, Xuesong Xu, Tianyu Zhang, Jiale Mi, Dong Wang, Dechao Zhang, Han Li, Song Yu, Yichen Zhang View a PDF of the paper titled Practical continuous-variable quantum key distribution using dynamic digital signal processing: security proof and experimental demonstration, by Lu Fan and 10 other authors View PDF HTML (experimental) Abstract:Digital signal processing technology has paved the way for the realization of high-speed continuous-variable quantum key distribution systems. However, existing security proofs are limited to static digital signal processing algorithms, while practical systems rely on dynamic multiple-input multiple-output algorithms to compensate for time-varying channel impairments. Our analysis reveals that the conventional dynamic algorithm, due to its non-unitary nature, systematically underestimates the excess noise, which in turn leads to security issues and the generation of insecure keys. To close this gap, we propose a secure algorithm model, mapping the dynamic algorithm to an equivalent physical optical model whose security can be rigorously assessed. Simulations illustrate the algorithm's non-unitary property and provide a quantitative analysis of the excess noise underestimation caused by the conventional algorithm. We further experimentally validate the necessity of the proposed modeling for dynamic digital signal processing, achieving a secret key rate of 14.4 Mbps based on estimated excess noise of 0.07 shot noise unit; whereas the conventional algorithm would have dangerously overestimated the key rate to 28.2 Mbps with noise of 0.008 shot noise unit. This work provides the essential security framework for dynamic digital signal processing, overcoming a critical impediment for the development of high-performance continuous-variable quantum key distribution systems. Comments: Subjects: Quantum Physics (quant-ph) Cite as: arXiv:2602.05206 [quant-ph] (or arXiv:2602.05206v1 [quant-ph] for this version) https://doi.org/10.48550/arXiv.2602.05206 Focus to learn more arXiv-issued DOI via DataCite (pending registration) Submission history From: Yi-Chen Zhang [view email] [v1] Thu, 5 Feb 2026 02:03:56 UTC (5,410 KB) Full-text links: Access Paper: View a PDF of the paper titled Practical continuous-variable quantum key distribution using dynamic digital signal processing: security proof and experimental demonstration, by Lu Fan and 10 other authorsView PDFHTML (experimental)TeX Source view license Current browse context: quant-ph new | recent | 2026-02 References & Citations INSPIRE HEP NASA ADSGoogle Scholar Semantic Scholar export BibTeX citation Loading... BibTeX formatted citation × loading... Data provided by: Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Code, Data and Media Associated with this Article alphaXiv Toggle alphaXiv (What is alphaXiv?) Links to Code Toggle CatalyzeX Code Finder for Papers (What is CatalyzeX?) DagsHub Toggle DagsHub (What is DagsHub?) GotitPub Toggle Gotit.pub (What is GotitPub?) Huggingface Toggle Hugging Face (What is Huggingface?) Links to Code Toggle Papers with Code (What is Papers with Code?) ScienceCast Toggle ScienceCast (What is ScienceCast?) Demos Demos Replicate Toggle Replicate (What is Replicate?) Spaces Toggle Hugging Face Spaces (What is Spaces?) Spaces Toggle TXYZ.AI (What is TXYZ.AI?) Related Papers Recommenders and Search Tools Link to Influence Flower Influence Flower (What are Influence Flowers?) Core recommender toggle CORE Recommender (What is CORE?) Author Venue Institution Topic About arXivLabs arXivLabs: experimental projects with community collaborators arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website. Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them. Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs. Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)