2004/03/18 by Masato Koashi · 140 citations
Computer Science · Physics and Astronomy · #Algorithm #Coherent states #Computer science #Computer security #Key (lock) #Phase (matter) #Photon #Physics #Pulse (music) #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum channel #Quantum cryptography #Quantum information #Quantum key distribution #Quantum mechanics #State (computer science) #Statistical physics #Telecommunications #Transmission (telecommunications) #quant-ph
paper · pdf · doi:10.1103/physrevlett.93.120501
published in Physical Review Letters 93(12), 120501 (American Physical Society) · 4 pages, 3 figures
arxiv created 2004/03/18 · openalex publication_date 2004/09/15 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We prove the unconditional security of a quantum key distribution protocol in which bit values are encoded in the phase of a weak coherent-state pulse relative to a strong reference pulse. In contrast with implementations in which a weak pulse is used as a substitute for a single-photon source, the achievable key rate is found to decrease only linearly with the transmission of the channel.