{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T18:07:17Z","timestamp":1790014037499,"version":"4.0.1"},"reference-count":34,"publisher":"Optica Publishing Group","issue":"28","license":[{"start":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T00:00:00Z","timestamp":1789948800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/doi.org\/10.1364\/OA_License_v2#VOR"},{"start":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T00:00:00Z","timestamp":1789948800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/opg.optica.org\/policies\/opg-tdm-policy.json"}],"funder":[{"name":"National Centre for Research and Development","award":["POLTAJ11\/2023\/5\/SEQOLOND\/2025"],"award-info":[{"award-number":["POLTAJ11\/2023\/5\/SEQOLOND\/2025"]}],"id":[{"id":"https:\/\/ror.org\/05pwfyy15","id-type":"ROR","asserted-by":"publisher"}]},{"name":"National Science and Technology Council"},{"name":"Ministry of Science and Higher Education","award":["DWD\/8\/0353\/2024"],"award-info":[{"award-number":["DWD\/8\/0353\/2024"]}],"id":[{"id":"https:\/\/ror.org\/05dwvd537","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":["opg.optica.org"],"crossmark-restriction":false},"short-container-title":["Appl. Opt."],"published-print":{"date-parts":[[2026,10,1]]},"abstract":"<jats:p>We report the experimental distribution of a cryptographic key based on binary intensity-modulation\/direct-detection (IM\/DD) transmission of an optical signal. The implemented secret key agreement protocol ensures security against passive wiretap eavesdropping, notably in the regime when the eavesdropper has an advantage in the intercepted signal strength over the legitimate recipient. Operating at a 1\u00a0GBaud symbol rate, the experimental fiber optic testbed yielded secret key rates between 43.5\u00a0Mbps at 61.1\u00a0km and 640\u00a0kbps at 81.6\u00a0km of the effective link length, with a 9% wiretap installed at the transmitter. The protocol performance was analyzed using a theoretical model incorporating transmitter noise and non-ideal key reconciliation efficiency. The presented results validate IM\/DD optical key distribution as an efficient low-complexity solution for protecting optical communication systems against the predominant physical-layer threat of wiretap eavesdropping.<\/jats:p>","DOI":"10.1364\/ao.607192","type":"journal-article","created":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T16:00:10Z","timestamp":1788192010000},"page":"9585","update-policy":"https:\/\/doi.org\/10.1364\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Experimental realization of optical key distribution under strong wiretap eavesdropping"],"prefix":"10.1364","volume":"65","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-6679-0447","authenticated-orcid":true,"given":"Mateusz","family":"Kucharczyk","sequence":"first","affiliation":[{"name":"Quantum Optical Technologies sp. z o.o."},{"name":"University of Warsaw"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marcin","family":"Jarzyna","sequence":"additional","affiliation":[{"name":"Quantum Optical Technologies sp. z o.o."},{"name":"University of Warsaw"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4038-0330","authenticated-orcid":true,"given":"Miko\u0142aj","family":"Lasota","sequence":"additional","affiliation":[{"name":"Nicolaus Copernicus University in Toru\u0144"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2478-2417","authenticated-orcid":true,"given":"Piotr","family":"Kolenderski","sequence":"additional","affiliation":[{"name":"Nicolaus Copernicus University in Toru\u0144"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2345-4147","authenticated-orcid":true,"given":"Jaros\u0142aw P.","family":"Turkiewicz","sequence":"additional","affiliation":[{"name":"Warsaw University of Technology"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5546-3115","authenticated-orcid":true,"given":"Patryk J.","family":"Urban","sequence":"additional","affiliation":[{"name":"Quantum Optical Technologies sp. z o.o."},{"name":"West Pomeranian University of Technology in Szczecin"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5389-6897","authenticated-orcid":true,"given":"Konrad","family":"Banaszek","sequence":"additional","affiliation":[{"name":"Quantum Optical Technologies sp. z o.o."},{"name":"University of Warsaw"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"285","published-online":{"date-parts":[[2026,9,21]]},"reference":[{"key":"ao-65-28-9585-R1","doi-asserted-by":"publisher","first-page":"725","DOI":"10.1109\/TIFS.2011.2141990","type":"journal-article","volume":"6","author":"Fok","year":"2011","journal-title":"IEEE Trans. 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All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.","name":"copyright","label":"Copyright"}]}}