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Auflistung nach Autor:in "Kaufmann, Stefan"

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  • Konferenzbeitrag
    diretto: A Toolkit for Distributed Reporting and Collaboration
    (Mensch & Computer 2011: überMEDIEN|ÜBERmorgen, 2011) Erb, Benjamin; Kaufmann, Stefan; Schlecht, Tobias; Schaub, Florian; Weber, Michael
    The goal of the diretto project is the creation of an extensible infrastructure and easy-to-use toolset for distributed on-site media reporting and collaborative event coverage in real-time. It empowers collocated users to participate dynamically in event reporting, and facilitates collaboration with remote users. For example, to cover public events or support disaster relief missions with on-site information. The diretto platform focuses on scalability to support large crowd participation. Our platform currently supports smartphone clients, a reporting solution for SLR cameras, and a rich web application for remote collaborators. diretto is easily extensible and can be tailored to mission-specific requirements.
  • Konferenzbeitrag
    Implementation and adaptation of the pseudonymous PKI for ubiquitous computing for car-2-car communication
    (Automotive - Safety & Security 2014, 2015) Kaufmann, Stefan
    Car-2-Car communication requires the use of pseudonymous public keys to ensure the vehicle's privacy by making its messages unlinkable over a longer period. The Pseudonymous PKI (PPKI) for Ubiquitous Computing by K. Zeng [Ze06] offers peer-side pseudonym generation, non-repudiation and an efficient revocation mechanism that excludes the revoked peers from the group of authorized participants. In addition, this work provides a new authorisation scheme that incorporates efficiently into the pseudonymous PKI, offers peer-side pseudonymous credential generation and preserves the peer's privacy during the initial authorisation obtainment from third party authentication authorities. The PKI scheme is also supplemented with a particular non-pseudonymous variation for roadside units as well as other adaptations based on Car-2-Car requirements. Finally, the signature verification performance and message sizes are analysed. We argue that the PPKI fulfils the security challenges of Car-2-Car communication and has advantages over a classical PKI.