Quantum Eavesdropping without Interception: An Attack Exploiting the Dead Time of Single Photon Detectors

The security of quantum key distribution (QKD) can easily be obscured if the eavesdropper can utilize technical imperfections of the actual implementation. Here we describe and experimentally demonstrate a very simple but highly effective attack which even does not need to intercept the quantum channel at all. Only by exploiting the dead time effect of single photon detectors the eavesdropper is able to gain (asymptotically) full information about the generated keys without being detected by state-of-the-art QKD protocols. In our experiment, the eavesdropper inferred up to 98.8% of the key correctly, without increasing the bit error rate between Alice and Bob significantly. Yet, we find an evenly simple and effective countermeasure to inhibit this and similar attacks

Risk governance in organizations

Dieses Buch dokumentiert 10 Jahre Risk-Governance-Forschung an der Universität Siegen. In 50 Beiträgen reflektieren Forscher und Praktiker Risk Governance vor dem Hintergrund ihrer eigenen Forschungen und/oder Erfahrungen und geben jeweils einen Entwicklungsimpuls für die Zukunft der Risk Governance. Das Buch zeigt die große Bandbreite und Tiefe des Forschungsgebietes auf und diskutiert Grundannahmen, Implementierungsfragen, die Rolle der Risk Governance als Transformationsmotor, ihre Wirkung in den verschiedenen betrieblichen Funktionen, Entwicklungsperspektiven und den Beitrag der Risk Governance zu einer nachhaltigen Ausrichtung von Unternehmen.This book documents 10 years of risk governance research at the University of Siegen. In 50 contributions, researchers and practitioners reflect on risk governance against the background of their own research and/or experience and provide a development impetus for the future of risk governance. The book shows the wide range and depth of the research field and discusses basic assumptions, implementation issues, the role of risk governance as transformation engine, its impact in the various operational functions, development perspectives, and the contribution of risk governance to a sustainable orientation of companies

Isolation and identification of the plasma membrane-associated intracellular protein reggie-2 from goldfish brain by chromatography and Fourier-transform ion cyclotron resonance mass spectrometry

The neuronal protein reggie-2 is localized at the cytoplasmic face of the plasma membrane and participates, together with reggie-1, in the formation of plasma membrane microdomains. Reggie-2 exhibits several potential phosphorylation sites but whether the relevant sites are modified accordingly is not yet known. In order to obtain a detailed, molecular characterization of the primary structure of the native protein, an effective procedure for the isolation of the different reggie proteins from animal tissue is required. The specific properties of the proteins, particularly their membrane association and low abundance, make approaches for isolation such as affinity chromatography and 2D gel electrophoresis unfeasible. This study describes a rapid and efficient procedure for the isolation of reggie-2 by use of two consecutive HPLC steps and subsequent SDS-PAGE. The protein fractions were characterized by SDS-PAGE and Western blot analysis as well as by mass spectrometry. In the primary structure analysis by matrix-assisted laser desorption-ionization mass spectrometry (MALDI-MS), the efficiency of high-resolution Fourier-transform ion cyclotron resonance-MALDI-MS was demonstrated, enabling the direct, unequivocal, and sensitive characterization of posttranslationally and/or chemically modified proteins