Scalable Quantum Key Distribution via GHZ Entanglement and Qubit Reuse

Quantum Physics arXiv:2608.21667 (quant-ph) [Submitted on 21 Aug 2026] Title:Scalable Quantum Key Distribution via GHZ Entanglement and Qubit Reuse Authors:Tasdiqul Islam, Rasman Mubtasim Swargo, Engin Arslan, Md Arifuzzaman View a PDF of the paper titled Scalable Quantum Key Distribution via GHZ Entanglement and Qubit Reuse, by Tasdiqul Islam and 2 other authors View PDF Abstract:Conventional Quantum Key Distribution (QKD) requires the transmission of qubits proportional to or exceeding the length of the key, as protocols such as BB84 transmit more qubits than the final key size due to basis sifting and privacy amplification. Since quantum networks are still in their infancy and have limited capacity, this overhead puts significant pressure on network resources. To address this issue, we propose a Multi-Qubit Greenberger--Horne--Zeilinger (GHZ) State-based QKD scheme that reduces the number of qubits transmitted over the quantum channel. The proposed method transmits one GHZ qubit between endpoints and reuses the resulting entanglement to convey multiple classical key bits with the help of Quantum Non-Demolition (QND) measurements. Under the stated assumptions on authenticated classical communication, local reset verification, and bounded-error QND discrimination, one can transfer $L$ classical bits by generating an (L+1)-qubit GHZ state and transferring one qubit to the remote party. We verify correctness using the NetSquid quantum network simulator: the protocol achieves 100\% raw-key fidelity for keys of length up to 12 bits under both ideal conditions and depolarizing noise up to p = 0.005 per round. We further show that the proposed QKD algorithm can be extended to multi-party QKD and server-client deployment. The proposed scheme offers a transmitted-qubit-efficient, noise-tolerant alternative for bandwidth-limited quantum networks. Comments: Subjects: Quantum Physics (quant-ph); Cryptography and Security (cs.CR); Networking and Internet Architecture (cs.NI) Cite as: arXiv:2608.21667 [quant-ph] (or arXiv:2608.21667v1 [quant-ph] for this version) https://doi.org/10.48550/arXiv.2608.21667 Focus to learn more arXiv-issued DOI via DataCite (pending registration) Submission history From: Md Arifuzzaman [view email] [v1] Fri, 21 Aug 2026 22:15:31 UTC (551 KB) Full-text links: Access Paper: View a PDF of the paper titled Scalable Quantum Key Distribution via GHZ Entanglement and Qubit Reuse, by Tasdiqul Islam and 2 other authorsView PDFTeX Source view license Current browse context: quant-ph new | recent | 2026-08 Change to browse by: cs cs.CR cs.NI 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?) 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?)