title: Quantum digital signatures without quantum memory.
abstract: Quantum digital signatures (QDSs) allow the sending of messages from one sender to multiple recipients, with the guarantee that messages cannot be forged or tampered with. Additionally, messages cannot be repudiated--if one recipient accepts a message, she is guaranteed that others will accept the same message as well. While messaging with these types of security guarantees are routinely performed in the modern digital world, current technologies only offer security under computational assumptions. QDSs, on the other hand, offer security guaranteed by quantum mechanics. All thus far proposed variants of QDSs require long-term, high quality quantum memory, making them unfeasible in the foreseeable future. Here, we present a QDS scheme where no quantum memory is required, which also needs just linear optics. This makes QDSs feasible with current technology.
authors.affiliation: School of Informatics, University of Edinburgh, Edinburgh EH8 9AB, United Kingdom and Division of Molecular Biology, Rud Bošković Institute, Bijenička cesta 54, P.P. 180, 10002 Zagreb, Croatia and SUPA, Institute for Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 1AS, United Kingdom.
authors.forename: Vedran
authors.initials: V
authors.lastname: Dunjko
authors.affiliation: SUPA, Institute for Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 1AS, United Kingdom and Physics Department, University of Athens, Panepistimiopolis 157-71, Ilisia Athens, Greece.
authors.forename: Petros
authors.initials: P
authors.lastname: Wallden
authors.affiliation: SUPA, Institute for Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 1AS, United Kingdom.
authors.forename: Erika
authors.initials: E
authors.lastname: Andersson
mesh_terms: D003142:Communication; D016494:Computer Security; D011789:Quantum Theory