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Wireless covert channels promise to exfiltrate information with high bandwidth by circumventing traditional access control mechanisms. Ideally, they are only accessible by the intended recipient and-for regular system users/operators-indistinguishable from normal operation. While a number of theoretical and simulation studies exist in literature, the(More)
Wireless networks based on visible light communication (VLC) are often considered to be resilient to eavesdropping by design, since light cannot penetrate most walls and objects. In this paper, we experimentally study the ability of a VLC eavesdropper to intercept and decode a transmission even while being outside of the direct beam. We design a testbed(More)
Next generation wireless networks utilizing millimeter waves (mm-waves) achieve extremely high data rates using narrow signal beams. Featuring a high directivity and being susceptible to blockage by objects, mm-waves are often assumed to be hard to intercept. However, small-scale objects within the beam cause reflections, thus enabling eavesdroppers to(More)
The steadily growing number of certification authorities (CAs) assigned to the Web Public Key Infrastructure (Web PKI) and trusted by current browsers imposes severe security issues. Apart from being impossible for relying entities to assess whom they actually trust, the current binary trust model implemented with the Web PKI makes each CA a single point of(More)
Current mm-wave indoor propagation analysis techniques have limited options when it comes to more than one transmitter and receiver. Experimental testbed hardware is expensive and state-of-the-art simulation methods, such as statistical channel models, are limited to specific scenarios. To overcome these problems, we present mmTrace, a fast deterministic(More)
The advantages of mm-wave communication technology with highly directional transmissions enable high data rates in dense wireless networks. Even though first consumer hardware is already available, specific propagation effects are not yet well understood. Analyses of wireless network behavior with mm-wave communication links are required to design efficient(More)
Hiermit versichere ich, die vorliegende Master-Thesis ohne Hilfe Dritter nur mit den angegebenen Quellen und Hilfsmitteln angefertigt zu haben. Alle Stellen, die aus Quellen entnommen wurden, sind als solche kenntlich gemacht. Diese Arbeit hat in gleicher oder ähnlicher Form noch keiner Prüfungsbehörde vorgelegen. Abstract This thesis' goal is to reduce the(More)
Securing visible light communication (VLC) systems on the physical layer promises to prevent against a variety of attacks. Recent work shows that the adaption of existing legacy radio wave physical layer security (PLS) mechanisms is possible with minor changes. Yet, many adaptations open new vulnerabilities due to distinct propagation characteristics of(More)
TETRA is a digital communication standard taking over from analog communication in various emergency services and governmental agencies in Europe since the late 1990s. TETRA has to meet stringent requirements for a dependable communication infrastructure as it is used in the public safety sector by professional users and first responders. In fact, TETRA is(More)