Dieter Sommer

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User centricity is a significant concept in federated identity management (FIM), as it provides for stronger user control and privacy. However, several notions of user-centricity in the FIM community render its semantics unclear and hamper future research in this area. Therefore, we consider user-centricity abstractly and establish a comprehensive taxonomy(More)
The shift from a paper-based to an electronic-based society has dramatically reduced the cost of collecting, storing and processing individuals' personal information. As a result, it is becoming more common for businesses to "profile" individuals in order to present more personalized offers as part of their business strategy. While such profiles can be(More)
Interactions in electronic media require mutual trust to be established, preferably through the release of certified information. Disclosing certificates for provisioning the required information often leads to the disclosure of additional information not required for the purpose of the interaction. For instance ordinary certificates unnecessarily reveal(More)
The PRIME project develops privacy enhancing identity management systems that allow users in various application areas such as e-commerce to regain control over their personal spheres. This paper introduces the PRIME technical architecture that also includes special trust-enhancing mechanisms, and shows how PRIME technologies can enhance privacy and trust(More)
Cobalt-ferrite nanoparticles (Co-Fe NPs) are attractive for nanotechnology-based therapies. Thus, exploring their effect on viability of seven different cell lines representing different organs of the human body is highly important. The toxicological effects of Co-Fe NPs were studied by in-vitro exposure of A549 and NCIH441 cell-lines (lung), precision-cut(More)
Journal of Computer Security 00 (2009) 1–38 1 DOI 10.3233/JCS-2009-0367 IOS Press 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10 11 11 12 12 13 13 14 14 15 15 16 16 17 17 18 18 19 19 20 20 21 21 22 22 23 23 24 24 25 25 26 26 27 27 28 28 29 29 30 30 31 31 32 32 33 33 34 34 35 35 36 36 37 37 38 38 39 39 40 40 41 41 42 42 43 43 Exploiting cryptography for(More)
The toxicological effects of cobalt nanoparticles (Co-NPs) aggregates were examined and compared with those of cobalt ions (Co-ions) using six different cell lines representing lung, liver, kidney, intestine, and the immune system. Dose-response curves were studied in the concentration range of 0.05-1.0 mM, employing(More)
We address the problem of privacy-preserving access control in distributed systems. Users commonly reveal more personal data than strictly necessary to be granted access to online resources, even though existing technologies, such as anonymous credential systems, offer functionalities that would allow for privacy-friendly authorization. An important reason(More)