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Current security proofs of QKD with detection-efficiency mismatch rely either on the assumption of the single-photon light source on the sender side or on the assumption of the single-photon input of the receiver side. These assumptions impose restrictions on the class of possible eavesdropping strategies. Here we present a rigorous security proof without these assumptions and, thus, solve this important problem and prove the security of QKD with detection-efficiency mismatch against general attacks (in the asymptotic regime). In particular, we adapt the decoy state method to the case of detection-efficiency mismatch.<\/jats:p>","DOI":"10.22331\/q-2022-07-22-771","type":"journal-article","created":{"date-parts":[[2022,7,22]],"date-time":"2022-07-22T09:47:02Z","timestamp":1658483222000},"page":"771","update-policy":"https:\/\/doi.org\/10.22331\/q-crossmark-policy-page","source":"Crossref","is-referenced-by-count":16,"title":["Security of quantum key distribution with detection-efficiency mismatch in the multiphoton case"],"prefix":"10.22331","volume":"6","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9541-0752","authenticated-orcid":false,"given":"Anton","family":"Trushechkin","sequence":"first","affiliation":[{"name":"Steklov Mathematical Institute of RAS, Steklov International Mathematical Center, Moscow 119991, Russia"},{"name":"Department of Mathematics and NTI Center for Quantum Communications, National University of Science and Technology MISIS, Moscow 119049, Russia"},{"name":"QRate, Skolkovo, Moscow 143025, Russia"}]}],"member":"9598","published-online":{"date-parts":[[2022,7,22]]},"reference":[{"key":"0","unstructured":"C. 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