{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,15]],"date-time":"2026-04-15T20:39:32Z","timestamp":1776285572680,"version":"3.50.1"},"reference-count":37,"publisher":"Verein zur Forderung des Open Access Publizierens in den Quantenwissenschaften","license":[{"start":{"date-parts":[[2023,9,21]],"date-time":"2023-09-21T00:00:00Z","timestamp":1695254400000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Emmy Noether DFG","award":["418294583"],"award-info":[{"award-number":["418294583"]}]},{"name":"Q.Link.X","award":["16KIS0865"],"award-info":[{"award-number":["16KIS0865"]}]},{"name":"QR.X","award":["16KISQ021"],"award-info":[{"award-number":["16KISQ021"]}]},{"name":"Einstein Research Unit","award":["ERU-2020-607"],"award-info":[{"award-number":["ERU-2020-607"]}]}],"content-domain":{"domain":["quantum-journal.org"],"crossmark-restriction":false},"short-container-title":["Quantum"],"abstract":"Sharing multi-partite quantum entanglement between parties allows for diverse secure communication tasks to be performed. Among them, conference key agreement (CKA) - an extension of key distribution to multiple parties - has received much attention recently. Interestingly, CKA can also be performed in a way that protects the identities of the participating parties, therefore providing a<\/mml:mi>n<\/mml:mi>o<\/mml:mi>n<\/mml:mi>y<\/mml:mi>m<\/mml:mi>i<\/mml:mi>t<\/mml:mi>y<\/mml:mi><\/mml:math>. In this work, we propose an anonymous CKA protocol for three parties that is implemented in a highly practical network setting. Specifically, a line of quantum repeater nodes is used to build a linear cluster state among all nodes, which is then used to anonymously establish a secret key between any three of them. The nodes need only share maximally entangled pairs with their neighbours, therefore avoiding the necessity of a central server sharing entangled states. This linear chain setup makes our protocol an excellent candidate for implementation in future quantum networks. We explicitly prove that our protocol protects the identities of the participants from one another and perform an analysis of the key rate in the finite regime, contributing to the quest of identifying feasible quantum communication tasks for network architectures beyond point-to-point.<\/jats:p>","DOI":"10.22331\/q-2023-09-21-1117","type":"journal-article","created":{"date-parts":[[2023,9,21]],"date-time":"2023-09-21T12:31:18Z","timestamp":1695299478000},"page":"1117","update-policy":"https:\/\/doi.org\/10.22331\/q-crossmark-policy-page","source":"Crossref","is-referenced-by-count":9,"title":["Anonymous conference key agreement in linear quantum networks"],"prefix":"10.22331","volume":"7","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9662-9337","authenticated-orcid":false,"given":"Jarn","family":"de Jong","sequence":"first","affiliation":[{"name":"Electrical Engineering and Computer Science, Technische Universit\u00e4t Berlin, 10587 Berlin, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9349-4075","authenticated-orcid":false,"given":"Frederik","family":"Hahn","sequence":"additional","affiliation":[{"name":"Electrical Engineering and Computer Science, Technische Universit\u00e4t Berlin, 10587 Berlin, Germany"},{"name":"Dahlem Center for Complex Quantum Systems, Freie Universit\u00e4t Berlin, 14195 Berlin, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3033-1292","authenticated-orcid":false,"given":"Jens","family":"Eisert","sequence":"additional","affiliation":[{"name":"Dahlem Center for Complex Quantum Systems, Freie Universit\u00e4t Berlin, 14195 Berlin, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1204-6009","authenticated-orcid":false,"given":"Nathan","family":"Walk","sequence":"additional","affiliation":[{"name":"Dahlem Center for Complex Quantum Systems, Freie Universit\u00e4t Berlin, 14195 Berlin, Germany"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4662-149X","authenticated-orcid":false,"given":"Anna","family":"Pappa","sequence":"additional","affiliation":[{"name":"Electrical Engineering and Computer Science, Technische Universit\u00e4t Berlin, 10587 Berlin, Germany"}]}],"member":"9598","published-online":{"date-parts":[[2023,9,21]]},"reference":[{"key":"0","doi-asserted-by":"publisher","unstructured":"Gl\u00e1ucia Murta, Federico Grasselli, Hermann Kampermann, and Dagmar Bru\u00df. ``Quantum conference key agreement: A review''. 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