2005/01/31 by W. -Y. Hwang, Won-Young Hwang
Computer Science · Mathematics · Physics and Astronomy · #Computer science #Computer security #Distribution (mathematics) #Genetics #Inequality #Key (lock) #Mathematical analysis #Mathematics #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum key distribution #Quantum mechanics #Random sequence #Sequence (biology) #Statistical physics #quant-ph
paper · pdf · doi:10.1103/physreva.71.052329
published as Physical Review A 71, 052329 (2005) · English corrected, 3 pages, RevTex
arxiv created 2005/03/22 · openalex publication_date 2005/05/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The Ekert 1991 quantum key distribution (QKD) protocol appears to be secure regardless of whatever devices legitimate users adopt for the protocol, as long as the devices give a result that violates Bell's inequality. However, this is not the case if they ignore nondetection events because Eve can make use of the detection loophole, as Larrson showed [Quantum Inf. Comput. 2, 434 (2002)]. We show that even when legitimate users take into account nondetection events Eve can successfully eavesdrop if the QKD system has been appropriately designed by the manufacturer. A loophole utilized here is that of ``free choice'' (or ``real randomness''). Local QKD devices with a pseudorandom sequence generator installed in them can apparently violate Bell's inequality.