Tighter Asymptotic Key Rates for Intensity-Correlated Decoy-State QKD via Nonlinear Programming
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Quantum Physics arXiv:2602.04966 (quant-ph) [Submitted on 4 Feb 2026] Title:Tighter Asymptotic Key Rates for Intensity-Correlated Decoy-State QKD via Nonlinear Programming Authors:Matej Pivoluska, Mateus Araújo View a PDF of the paper titled Tighter Asymptotic Key Rates for Intensity-Correlated Decoy-State QKD via Nonlinear Programming, by Matej Pivoluska and Mateus Ara\'ujo View PDF HTML (experimental) Abstract:Decoy-state QKD with phase-randomized weak coherent pulses is typically analyzed assuming independent, precisely prepared intensities. Real sources, however, can exhibit correlated intensity drift across rounds, potentially leaking intensity information and breaking the standard decoy-state reduction to linear programs. Cauchy--Schwarz (CS) constraints can restore security by coupling $n$-photon yields across intensities, but they introduce nonlinear square-root constraints that are commonly handled via outer linearisation around channel-model-based reference points. We propose a reproducible alternative: first solve the full CS-constrained parameter-estimation problems using the interior-point nonlinear solver IPOPT, then use the resulting candidate solution as the linearisation point for the outer optimisation that certifies a valid lower bound on the asymptotic key rate. Simulations for both coarse-grained model-independent correlations and fine-grained truncated-Gaussian models show consistently tighter key-rate bounds than canonical reference points, and in some cases allow certifying optimality when both optimisation stages coincide. Comments: Subjects: Quantum Physics (quant-ph) Cite as: arXiv:2602.04966 [quant-ph] (or arXiv:2602.04966v1 [quant-ph] for this version) https://doi.org/10.48550/arXiv.2602.04966 Focus to learn more arXiv-issued DOI via DataCite (pending registration) Submission history From: Matej Pivoluska [view email] [v1] Wed, 4 Feb 2026 19:00:05 UTC (47 KB) Full-text links: Access Paper: View a PDF of the paper titled Tighter Asymptotic Key Rates for Intensity-Correlated Decoy-State QKD via Nonlinear Programming, by Matej Pivoluska and Mateus Ara\'ujoView 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?)