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Auflistung nach Autor:in "Voigt, Sebastian"

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  • Konferenzbeitrag
    An access control protocol for peer-to-peer applications using asymmetric cryptography
    (INFORMATIK 2006 – Informatik für Menschen, Band 1, 2006) Voigt, Sebastian
    Virtual rooms and common information spaces are being used more and more frequently. In addition to internet-based solutions, ad-hoc InfoSpaces have been proposed. Their security has not been sufficiently investigated. This paper proposes a new protocol for peer-to-peer data exchange with support for access control for operations in the virtual rooms. Access rights for operations are kept in access control matrices and the security layer allows only operations from clients which are marked as allowed in the access control matrix. The protocol is based on the idea of hiding the identity of all peer-to-peer participants. Thus this protocol offers anonymity and full peer-to-peer support using asymmetric cryptography to distribute the access control matrices. This works without any central authority.
  • Konferenzbeitrag
    Live-Manuskript - Ein Werkzeug zur kollaborativen Erstellung von Notizen und Mitschriften
    (DeLFI 2010 - 8. Tagung der Fachgruppe E-Learning der Gesellschaft für Informatik e.V., 2010) Groß, Andreas; Voigt, Sebastian; Janda, Thomas; Jacob, Matthias; Schilf, Patrick
    Zur Nachbereitung von Vorträgen, Meetings und Präsentationen hat sich die Notiz auf Papier beim Zuhörer als einfaches und schnelles Arbeitsmittel etabliert. Doch das analoge Medium lässt sich gerade bei der späteren Weiternutzung nur bedingt reorganisieren und effizient durchsuchen. Auch die Kombination mit den Mitschriften anderer Zuhörer gestaltet sich schwierig und wird daher nur selten durchgeführt, womit Synergieeffekte oft verloren gehen. Das in diesem Bericht beschriebene webbasierte \?Live-Manuskript“ beschreibt eine mögliche Lösung, Mitschriften kollaborativ zu erstellen.
  • Zeitschriftenartikel
    Making Digital Freemium Business Models a Success: Predicting Customers’ Lifetime Value via Initial Purchase Information
    (Business & Information Systems Engineering: Vol. 58, No. 2, 2016) Voigt, Sebastian; Hinz, Oliver
    In digital freemium business models such as those of online games or social apps, a large share of overall revenue derives from a small portion of the user base. Companies operating in these and similar businesses are increasingly constructing forecasting models with which to identify potential heavy users as early as possible and create special retention measures to suit those users’ needs. In our study, we observe three digital freemium companies that sell virtual credits and investigate to what extent initial purchase information can be used to determine a given customer’s lifetime value. We find that customers represent higher future lifetime values if they (a) make a purchase early after registration, (b) spend a significant amount on their initial purchase, and (c) use credit cards to purchase credits. In addition, we see that users tend to spend increasing amounts on subsequent purchases.