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...

The problem of'controlling access to multimedia multicasts requires the distribution and maintenance of keying information. The conventional approach to distributing keys is to use a channel independent of the multimedia content. We propose a second approach that involves the use of an data-dependent channel, and can be achieved for multimedia by using data embedding techniques. Using data embe...

Quantum key distribution (QKD) provides a way for distribution of secure key in at least two parties which they initially share. And there are many protocols for providing a secure key i.e. BB84 protocol, SARG04 protocol, E91 protocol and many more. In this paper all the concerned protocols that share a secret key is explained and comparative study of all protocols shown.

„App platforms” are electronic software distribution markets for mobile devices like smartphones or tablets. They have gained popularity after Apple launched its AppStore in 2008. Since then, app platforms have transformed the entire mobile communication industry including mobile network operators, device producers, software suppliers, content providers, advertisers, etc. Platforms (like AppSto...

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.