Torsten Franz

Implementation of continuous-variable quantum key distribution with composable and one-sided-device-independent security against coherent attacks.

Tobias Gehring, 2 Vitus Händchen, Jörg Duhme, Fabian Furrer, Torsten Franz, 5 Christoph Pacher, Reinhard F. Werner, and Roman Schnabel 7, ∗ Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut) and Institut für Gravitationsphysik, Leibniz Universität Hannover, Callinstraße 38, 30167 Hannover, Germany Department of Physics, Technical University of Denmark, Fysikvej, 2800 Kgs. Lyngby, Denmark Institut für Theoretische Physik, Leibniz Universität Hannover, Appelstraße 2, 30167 Hannnover, Germany Department of Physics, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan, 113-0033 Institut für Fachdidaktik der Naturwissenschaften, Technische Universität Braunschweig, Bienroder Weg 82, 38106 Braunschweig, Germany Digital Safety & Security Department, AIT Austrian Institute of Technology GmbH, 1220 Vienna, Austria Institut für Laserphysik und Zentrum für Optische Quantentechnologien, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, GermanySecret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution this is achieved without relying on the hardness of mathematical problems, which might be compromised by improved algorithms or by future quantum computers. State-of-the-art quantum key distribution requires composable security against coherent attacks for a finite number of distributed quantum states as well as robustness against implementation side channels. Here we present an implementation of continuous-variable quantum key distribution satisfying these requirements. Our implementation is based on the distribution of continuous-variable Einstein–Podolsky–Rosen entangled light. It is one-sided device independent, which means the security of the generated key is independent of any memoryfree attacks on the remote detector. Since continuous-variable encoding is compatible with conventional optical communication technology, our work is a step towards practical implementations of quantum key distribution with state-of-the-art security based solely on telecom components.

Strong Einstein-Podolsky-Rosen entanglement from a single squeezed light source

Einstein-Podolsky-Rosen (EPR) entanglement is a criterion that is more demanding than just certifying entanglement. We theoretically and experimentally analyze the low-resource generation of bipartite continuous-variable entanglement, as realized by mixing a squeezed mode with a vacuum mode at a balanced beam splitter, i.e., the generation of so-called vacuum-class entanglement. We find that in order to observe EPR entanglement the total optical loss must be smaller than

Quantum Cryptography as a Retrodiction Problem

33.3

Continuous Variable Quantum Key Distribution: Finite-Key Analysis of Composable Security against Coherent Attacks

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Gaussian Entanglement for Quantum Key Distribution from a Single-Mode Squeezing Source

. However, arbitrarily strong EPR entanglement is generally possible with this scheme. We realize continuous-wave squeezed light at

Verschränkung – Schlüssel zur Quantenwelt. Quanteninformationstheorie Teil 1: Grundlagen

1550

Geheime Nachrichten und schnelle Rechner. Quanteninformationstheorie Teil 2: Anwendungen

nm with up to

Erratum: Continuous Variable Quantum Key Distribution: Finite-Key Analysis of Composable Security Against Coherent Attacks [Phys. Rev. Lett. 109, 100502 (2012)]

9.9

Arbitrary-Attack-Proof Quantum Key Distribution Without Single Photons

dB of nonclassical noise reduction, which is the highest value at a telecom wavelength so far. Using two phase-controlled balanced homodyne detectors we observe an EPR covariance product of