2016/04/13 by Callum Croal, Christian Peuntinger, Bettina Heim +6 · 3 citations
Computer Science · Mathematics · Physics and Astronomy · #Blind signature #Computer science #Computer security #Digital signature #Hash function #Heterodyne (poetry) #Mathematics #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum cryptography #Quantum information #Quantum key distribution #Quantum mechanics #Signature (topology) #Telecommunications #Transmission (telecommunications) #quant-ph
paper · pdf · doi:10.1103/physrevlett.117.100503
published as Phys. Rev. Lett. 117, 100503 (2016)
arxiv created 2016/04/13 · openalex publication_date 2016/09/02 · arxiv updated 2016/09/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Digital signatures guarantee the authorship of electronic communications. Currently used "classical" signature schemes rely on unproven computational assumptions for security, while quantum signatures rely only on the laws of quantum mechanics to sign a classical message. Previous quantum signature schemes have used unambiguous quantum measurements. Such measurements, however, sometimes give no result, reducing the efficiency of the protocol. Here, we instead use heterodyne detection, which always gives a result, although there is always some uncertainty. We experimentally demonstrate feasibility in a real environment by distributing signature states through a noisy 1.6 km free-space channel. Our results show that continuous-variable heterodyne detection improves the signature rate for this type of scheme and therefore represents an interesting direction in the search for practical quantum signature schemes. For transmission values ranging from 100% to 10%, but otherwise assuming an ideal implementation with no other imperfections, the signature length is shorter by a factor of 2 to 10. As compared with previous relevant experimental realizations, the signature length in this implementation is several orders of magnitude shorter.