2013/02/07 by Satoshi Sunohara, Kiyoshi Tamaki, Sunohara, Satoshi +3 · 1 citation
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum Physics (quant-ph) #quant-ph
paper · pdf · doi:10.48550/arxiv.1302.1701
6 pages, two-column format, 5 figures, layout corrected
openalex publication_date 2013/02/07 · arxiv created 2013/02/08 · arxiv updated 2013/02/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
For the realization of quantum key distribution, it is important to investigate its security based on a mathematical model that captures properties of the actual devices used by the legitimate users. Recently, Ferenczi, et. al. (Phys. Rev. A 86 042327 (2012)) pointed out potential influences that the losses in phase modulators and/or the unbalance in the transmission rate of beam splitters may have on the security of the phase-encoded BB84 and analyzed the security of this scheme, which is called the unbalanced BB84. In this paper, we ask whether blindly applying the post-processing of the balanced BB84 to the unbalanced BB84 would lead to an insecure key or not, and we conclude that we can safely distill a secure key even with this post-processing. It follows from our proof that as long as the unbalances are basis-independent, our conclusion holds even if the unbalances are unknown and fluctuate in time.