2009/02/28 by Denis Sych, Gerd Leuchs · 1 citation
Computer Science · Physics and Astronomy · #Algorithm #Bit error rate #Coherent states #Computer science #Decoding methods #Direct-conversion receiver #Homodyne detection #Keying #Modulation (music) #Phase-shift keying #Physics #Postselection #Protocol (science) #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum cryptography #Quantum information #Quantum information science #Quantum key distribution #Quantum mechanics #SIGNAL (programming language) #Telecommunications #quant-ph
paper · pdf · doi:10.1088/1367-2630/12/5/053019
11 pages, 2 figures, 1 table. Comments welcome
arxiv created 2009/12/25 · openalex publication_date 2010/05/13 · arxiv updated 2015/05/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present a protocol for quantum key distribution using discrete modulation of coherent states of light. Information is encoded in the variable phase of coherent states which can be chosen from a regular discrete set ranging from binary to continuous modulation similar to phase-shift keying in classical communication. Information is decoded by simultaneous homodyne measurement of both quadratures and requires no active choice of basis. The protocol utilizes either direct or reverse reconciliation both with and without postselection. We analyze the security of the protocol and show how to enhance it by the optimal choice of all variable parameters of the quantum signal.