05 Fakultät Informatik, Elektrotechnik und Informationstechnik

Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/6

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1998 - 19994

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Institute: search.filters.UBSInstitut.Institut für Parallele und Verteilte SystemeStart date: 1993End date: 1999Author: search.filters.author.Hohl, Fritz

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Now showing 1 - 4 of 4
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    ATOMAS : a transaction-oriented open multi agent system; final report
    (1998) Straßer, Markus; Baumann, Joachim; Hohl, Fritz; Schwehm, Markus; Rothermel, Kurt
    The electronic marketplace of the future will consist of a large number of services located on an open, distributed and heterogeneous platform, which will be used by an even larger number of clients. Mobile Agent Systems are considered to be a precondition for the evolution of such an electronic market. They can provide a flexible infrastructure for this market, i.e. for the installation of new services by service agents as well as for the utilization of these services by client agents. Mobile Agent Systems basically consist of a number of locations and agents. Locations are (logical) abstractions for (physical) hosts in a computer network. The network of locations serves as a unique and homogeneous platform, while the underlying network of hosts may be heterogeneous and widely distributed. Locations therefore have to guarantee independence from the underlying hard- and software. To make the Mobile Agent System an open platform, the system furthermore has to guarantee security of hosts against malicious attacks.
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    AIDA I - Abschlußbericht
    (1998) Hohl, Fritz; Baumann, Joachim; Rothermel, Kurt; Schwehm, Markus; Straßer, Markus
    In diesem Bericht geht es um die Zusammenfassung der Erkenntnisse, die im Verlauf der ersten Phase des AIDA-Projektes bis September 1997 gewonnen wurden. AIDA ist ein Projekt, das von der Deutschen Forschungsgemeinschaft (DFG) finanziert wird. Das Thema dieses Projektes sind mobile Agenten, also Einheiten, die aus Code, Daten und Zustand bestehen und sich selbständig in einem Netzwerk bewegen können. Das Ziel von AIDA I war es, auf der Grundlage eines allgemeinen Verarbeitungsmodells flexible Systemmechanismen für verteilte, agentenbasierte Systeme zu entwickeln.
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    A protocol to detect malicious hosts attacks by using reference states
    (1999) Hohl, Fritz
    To protect mobile agents from attacks by their execution environments, or hosts, one class of protection mechanisms uses 'reference states' to detect modification attacks. Reference states are agent states that have been produced by non-attacking, or reference hosts. This paper presents a new protocol using reference states by modifying an existing approach, called 'traces'. In contrast to the original approach, this new protocol offers a model, where the execution on one host is checked unconditionally and immediately on the next host, regardless of whether this host is trusted or untrusted. This modification preserves the qualitative advantages like asynchronous execution, but also introduces two new problems: input to the execution session on one host cannot be held secret to a second host, and collaboration attacks of two consecutive hosts are possible. The overhead needed for the protocol roughly doubles the cost of the mobile agent execution.
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    Nexus - an open global infrastructure for spatial-aware applications
    (1999) Hohl, Fritz; Kubach, Uwe; Leonhardi, Alexander; Rothermel, Kurt; Schwehm, Markus
    Due to the lack of a generic platform for location- and spatial-aware systems, many basic services have to be reimplemented in each application that uses spatial-awareness. A cooperation among different applications is also difficult to achieve without a common platform. In this paper we present a platform that solves these problems. It provides an infrastructure that is based on computer models of regions of the physical world, which are augmented by virtual objects. We show how virtual objects make the integration of existing information systems and services in spatial-aware systems easier. Furthermore, our platform supports interactions between the computer models and the real world and integrates single models in a global 'Augmented World'.