We consider quantum key distribution in the device-independent scenario, i.e., where the legitimate parties do not know (or trust) the exact specification of their apparatus. We show how secure key distribution can be realized against the most general attacks by a quantum adversary under the condition that measurements on different subsystems by the honest parties commute.

Karol Horodecki, Micha l Horodecki, Pawe l Horodecki, Debbie Leung, Jonathan Oppenheim Department of Mathematics, Physics and Computer Science, University of Gdańsk, 80–952 Gdańsk, Poland Faculty of Applied Physics and Mathematics, Technical University of Gdańsk, 80–952 Gdańsk, Poland Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario, N2L1N8, Canada and Department of Ap...

Herd behaviour in financial markets is a recurring phenomenon that exacerbates asset price volatility, and is considered a possible contributor to market fragility. While numerous studies investigate herd behaviour in financial markets, it is often considered without reference to the pricing of financial instruments or other market dynamics. Here, a trader interaction model based upon informati...

We consider the notion of canonical attacks, which are the cryptographic analog of the canonical forms of a one-mode Gaussian channel. Using this notion, we explore the connections between the degradability properties of the channel and its security for quantum key distribution. Finally, we also show some relations between canonical attacks and optimal Gaussian cloners.

Reply to Comments on " Quantum Key Distribution for d-level systems for generalized Bell states " [Phys. Rev. A, 052331, (2002)] and " Quantum secret sharing based on a reusable Greenberger-Horne-Zeilinger states as secure carriers " [Phys. Abstract We show that the criticisms of two recent comments [1, 2] on the insecurity of quantum key distributions proposed in [3] and [4] and the secret sha...

Der sicheren Übertragung und Aufbewahrung vertraulicher Daten kommt in unserer von Information dominierten Gesellschaft immer grössere Bedeutung zu. Die heute gebräuchlichen Verfahren zur Datenverschlüsselung bieten allerdings nur berschränkte, so-genannt berechenmässige, Sicherheit. Das bedeutet, dass diese prinzipiell von einem Angreifer, der über genügend Rechenleistung (zum Beispiel einen, ...

We report on a feasibility study of a free-space Quantum Key Distribution setup operating at a mid-infrared wavelength. Alice sends polarization-coded pseudo-single photons from a Quantum Cascade Laser at 4.6 μm to Bob, who uses a nonlinear crystal and a Silicon Avalanche Photodiode to perform the detection via Sum Frequency Generation. Theoretical predictions, based on a proof-of-principle exp...

in this paper, we derive the exact analytical expressions for the shannon entropy of generalized orderstatistics from pareto-type and related distributions.