2007/11/30 by Ryutaroh Matsumoto, Shun Watanabe · 2 citations
Computer Science · Physics and Astronomy · #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #quant-ph
paper · pdf · doi:10.1093/ietfec/e91-a.10.2870
published as IEICE Trans. Fundamentals, vol. 91, no. 10, pp. 2870-2873, October 2008 · 5 pages, no figure, ieice.cls. Title was changed from version 1. To appear in IEICE Trans. Fundamentals (http://ietfec.oxfordjournals.org/), vol. E91-A, no. 10, Oct. 2008
arxiv created 2008/06/09 · openalex publication_date 2008/10/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We consider the mismatched measurements in the BB84 quantum key distribution protocol, in which measuring bases are different from transmitting bases. We give a lower bound on the amount of a secret key that can be extracted from the mismatched measurements. Our lower bound shows that we can extract a secret key from the mismatched measurements with certain quantum channels, such as the channel over which the Hadamard matrix is applied to each qubit with high probability. Moreover, the entropic uncertainty principle implies that one cannot extract the secret key from both matched measurements and mismatched ones simultaneously, when we use the standard information reconciliation and privacy amplification procedure.