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Rev. Lett."],"accepted":{"date-parts":[[2025,9,25]]},"abstract":"<jats:p>Conference key agreement aims to establish shared, private randomness among many separated parties in a network. Device-independent conference key agreement (DICKA) is a variant in which the source and the measurement devices used by each party need not be trusted. So far, DICKA protocols largely fall into two categories: those that rely on violating a joint Bell inequality using genuinely multipartite entangled states and those that concatenate many bipartite protocols. The question of whether a hybrid protocol exists, where a multipartite Bell inequality can be violated using only bipartite entanglement, was asked by Grasselli  []. We answer this question affirmatively, by constructing an asymptotically secure DICKA protocol achieving the same rate as the concatenation of bipartite device-independent quantum key distribution, yet relying on a single joint Bell violation. Our results prompt further discussion on the benefits of multipartite entanglement for DICKA over its bipartite alternative, and we give an overview of different arguments for near-term devices.<\/jats:p>","DOI":"10.1103\/v4s8-3zl5","type":"journal-article","created":{"date-parts":[[2025,9,25]],"date-time":"2025-09-25T18:33:56Z","timestamp":1758825236000},"update-policy":"https:\/\/doi.org\/10.1103\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Genuine Multipartite Entanglement is Not Necessary for Standard Device-Independent Conference Key Agreement"],"prefix":"10.1103","volume":"135","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7950-3844","authenticated-orcid":true,"given":"Lewis","family":"Wooltorton","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/04m01e293","id-type":"ROR","asserted-by":"publisher"}],"name":"University of York"},{"id":[{"id":"https:\/\/ror.org\/0524sp257","id-type":"ROR","asserted-by":"publisher"}],"name":"University of Bristol"},{"id":[{"id":"https:\/\/ror.org\/0315e5x55","id-type":"ROR","asserted-by":"publisher"}],"name":"Inria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9593-0136","authenticated-orcid":true,"given":"Peter","family":"Brown","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01naq7912","id-type":"ROR","asserted-by":"publisher"}],"name":"T\u00e9l\u00e9com Paris"},{"id":[{"id":"https:\/\/ror.org\/0315e5x55","id-type":"ROR","asserted-by":"publisher"}],"name":"Inria"},{"id":[{"id":"https:\/\/ror.org\/057er4c39","id-type":"ROR","asserted-by":"publisher"}],"name":"LTCI"},{"id":[{"id":"https:\/\/ror.org\/042tfbd02","id-type":"ROR","asserted-by":"publisher"}],"name":"Institut Polytechnique de Paris"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3591-0576","authenticated-orcid":true,"given":"Roger","family":"Colbeck","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/04m01e293","id-type":"ROR","asserted-by":"publisher"}],"name":"University of York"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"16","published-online":{"date-parts":[[2025,11,26]]},"reference":[{"key":"v4s8-3zl5Cc2R1","doi-asserted-by":"publisher","DOI":"10.26421\/QIC7.8-1","type":"journal-article"},{"key":"v4s8-3zl5Cc3R1","doi-asserted-by":"publisher","DOI":"10.1088\/1367-2630\/aa8487","type":"journal-article"},{"key":"v4s8-3zl5Cc4R1","doi-asserted-by":"publisher","DOI":"10.1088\/1367-2630\/aaec34","type":"journal-article"},{"key":"v4s8-3zl5Cc5R1","doi-asserted-by":"publisher","DOI":"10.1088\/1367-2630\/ab573e","type":"journal-article"},{"key":"v4s8-3zl5Cc6R1","doi-asserted-by":"publisher","DOI":"10.1002\/qute.202000025","type":"journal-article"},{"key":"v4s8-3zl5Cc7R1","doi-asserted-by":"publisher","DOI":"10.1126\/sciadv.abe0395","type":"journal-article"},{"key":"v4s8-3zl5Cc8R1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevApplied.19.064017","type":"journal-article"},{"key":"v4s8-3zl5Cc9R1","doi-asserted-by":"publisher","DOI":"10.1038\/s41534-023-00750-4","type":"journal-article"},{"key":"v4s8-3zl5Cc10R1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevA.97.022307","type":"journal-article"},{"key":"v4s8-3zl5Cc11R1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevA.100.026301","type":"journal-article"},{"key":"v4s8-3zl5Cc12R1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevA.100.026302","type":"journal-article"},{"key":"v4s8-3zl5Cc13R1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevResearch.2.023251","type":"journal-article"},{"key":"v4s8-3zl5Cc14R1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRev.47.777","type":"journal-article"},{"key":"v4s8-3zl5Cc15R1","volume-title":"Speakable and Unspeakable in Quantum Mechanics","author":"J.\u2009S. 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See Supplemental Material [30] for details.","type":"other"},{"key":"v4s8-3zl5Cc55R1","unstructured":"For the purposes of this proof-of-principle demonstration, this threshold is set to the maximum Bell violation (cf.\u00a0Proposition\u00a0t2).","type":"other"},{"key":"v4s8-3zl5Cc56R1","unstructured":"Additionally, all parties need to release a fraction of their generation data to perform an alignment test with Alice. If the fraction of matched outcomes is below a threshold, they will also abort.","type":"other"},{"key":"v4s8-3zl5Cc57R1","unstructured":"In the event of maximum Bell violation, the key distillation process is trivial, since all raw key bits are secure.","type":"other"},{"key":"v4s8-3zl5Cc58R1","unstructured":"Recall, given that the protocol did not abort, all parties agree on their classical variable TA\/B\/C\u2261T.","type":"other"},{"key":"v4s8-3zl5Cc59R1","doi-asserted-by":"publisher","DOI":"10.1007\/s00220-020-03839-5","type":"journal-article"},{"key":"v4s8-3zl5Cc60R1","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-017-02307-4","type":"journal-article"},{"key":"v4s8-3zl5Cc61R1","doi-asserted-by":"publisher","DOI":"10.26421\/QIC7.1-2-1","type":"journal-article"},{"key":"v4s8-3zl5Cc62R1","doi-asserted-by":"publisher","DOI":"10.1088\/1367-2630\/aafef6","type":"journal-article"},{"key":"v4s8-3zl5Cc63R1","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevA.111.012436","type":"journal-article"},{"key":"v4s8-3zl5Cc64R1","doi-asserted-by":"publisher","DOI":"10.1109\/TIT.2016.2526018","type":"journal-article"},{"key":"v4s8-3zl5Cc65R1","doi-asserted-by":"publisher","DOI":"10.1109\/ACCESS.2021.3113939","type":"journal-article"},{"key":"v4s8-3zl5Cc66R1","doi-asserted-by":"publisher","DOI":"10.1088\/1367-2630\/abef98","type":"journal-article"}],"container-title":["Physical Review Letters"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.aps.org\/article\/10.1103\/v4s8-3zl5","content-type":"unspecified","content-version":"vor","intended-application":"syndication"},{"URL":"http:\/\/harvest.aps.org\/v2\/journals\/articles\/10.1103\/v4s8-3zl5\/fulltext","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,11,26]],"date-time":"2025-11-26T12:19:30Z","timestamp":1764159570000},"score":1,"resource":{"primary":{"URL":"https:\/\/link.aps.org\/doi\/10.1103\/v4s8-3zl5"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11,26]]},"references-count":64,"journal-issue":{"issue":"22","published-print":{"date-parts":[[2025,11]]}},"URL":"https:\/\/doi.org\/10.1103\/v4s8-3zl5","relation":{"has-preprint":[{"id-type":"doi","id":"10.48550\/arXiv.2503.21290","asserted-by":"subject"}]},"ISSN":["0031-9007","1079-7114"],"issn-type":[{"value":"0031-9007","type":"print"},{"value":"1079-7114","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,11,26]]},"assertion":[{"value":"2025-04-01","name":"date_received","label":"Date Received","group":{"name":"publication_dates","label":"Publication dates"}},{"value":"Published by the American Physical Society. All rights are reserved, including those for text and data mining, AI training, and similar technologies.","name":"copyright_statement","label":"Copyright statement","group":{"name":"copyright","label":"copyright"}},{"value":"2025","name":"copyright_year","label":"Copyright year","group":{"name":"copyright","label":"copyright"}},{"value":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/","name":"creative_commons_license","label":"Creative Commons license","group":{"name":"licenses","label":"Licenses"}},{"value":"\u00a92025 The authors","name":"copyright_holder","label":"Copyright holder","group":{"name":"copyright","label":"copyright"}}],"article-number":"220803"}}