Jiska Classen

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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)
Incorporation of the channel-forming antibiotic gramicidin into the membrane of human erythrocytes highly (up to 30-fold) enhances rates of reorientation (flip) of lysophosphatidylcholine and palmitoylcarnitine to the inner membrane layer after their primary incorporation into the outer layer. Despite the high increase of flip rates by gramicidin, the(More)
Johannes Braun a,∗, Florian Volk b, Jiska Classen c, Johannes Buchmann a and Max Mühlhäuser b a Theoretical Computer Science, Cryptography and Computer Algebra, Technische Universität Darmstadt, Darmstadt, Germany E-mails: {jbraun, buchmann}@cdc.informatik.tu-darmstadt.de b Telecooperation Lab, Technische Universität Darmstadt and CASED, Darmstadt, Germany(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)
Tens of millions of wearable fitness trackers are shipped yearly to consumers who routinely collect information about their exercising patterns. Smartphones push this health-related data to vendors’ cloud platforms, enabling users to analyze summary statistics on-line and adjust their habits. Third-parties including health insurance providers now offer(More)
While radio-based indoor localization schemes achieve decimeter-scale accuracy, they typically require precise reference measurements, multiple infrastructure nodes, or a multi-RF-chain anchor. In this paper, we propose Pseudo LATeration (PLAT), an indoor localization protocol that requires only a single RF chain infrastructure anchor and does not require(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)
In the current Web Public Key Infrastructure (Web PKI), few central instances have the power to make trust decisions. From a system's perspective, it has the side effect that every Certification Authority (CA) becomes a single point of failure (SPOF). In addition, trust is no individual matter per user, what makes trust decisions hard to revise. Hence, we(More)