[HGI-News] HGI-Seminar 05.12.2005 and 12.12.2005 (Contributory Group Key Agreement Protocols for Mobile Ad Hoc Groups)

[Newsletter des Horst Görtz Instituts]

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          Zweiteiliges Miniseminar -- Mini-Seminar in two parts
Contributory Group Key Agreement Protocols for Mobile Ad Hoc Groups


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                          Part 1 - Erster Teil

                               Lijun Liao
                          Ruhr-University Bochum

                  Montag, 05.12.2005, 13:15 Uhr, IC 4/39

              TFAN: Tree-based Group Key Agreement Framework
                       for Mobile Ad-Hoc Networks


Abstract: Design of protocols for mobile ad-hoc networks (MANETs) is
generally tricky compared to wired networks, because on the one hand
the increased communication constraints given by the limited bandwidth
and frequent network failures, and on the other hand the additional
computation and memory constraints due to performance limitations of
mobile devices must be considered. We focus on the problem of the
establishment of the shared key in mobile ad-hoc groups. This task can
be achieved by means of a contributory group key agreement (CGKA)
protocol that allows group members to compute the group key based on
their individual contributions providing verifiable trust relationship
between participants. As shown in this paper there exists currently no
CGKA protocol for mobile ad-hoc networks that provides an optimal
trade-off between communication and computation efficiency. Based on
the comparison results of most suitable CGKA protocols we propose a new
framework for the group key agreement in mobile ad-hoc networks.
Theoretical analysis and experimental results show that our framework
achieves optimal communication and computation efficiency compared to
other protocols.


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                         Part 2 - Zweiter Teil

                              Mark Manulis
                          Ruhr-University Bochum

                  Montag, 12.12.2005, 13:15 Uhr, IC 4/39


            Key Agreement in Heterogeneous Mobile Ad Hoc Groups

Abstract: Security of various group-oriented applications for mobile
ad-hoc groups requires a group secret shared between all participants.
Contributory group key agreement (CGKA) protocols, originally designed
for dynamic peer groups in local- and wide-area wired networks, can be
adopted to mobile ad-hoc scenarios because of the similar security
requirements and trust relationship between participants. Essential is
the absence of any trusted central authority (e.g., a group manager)
that actively participates in the computation of the group key. Members
of spontaneously formed mobile ad-hoc groups are usually equipped with
different kinds of mobile devices, e.g., laptops, PDAs, and mobile
phones. Considering performance capabilities of the involved mobile
devices we distinguish between homogeneous and heterogeneous mobile
ad-hoc groups. On one hand heterogeneity opens a new way of designing
the CGKA protocols considering performance of the devices, on the other
hand it states additional security requirements as shown throughout
this paper. We propose a first CGKA protocol for heterogeneous mobile
ad hoc groups that fulfills not only common security requirements for
CGKA protocols but also additional requirements specified by our model.
The main idea behind our protocol is a fair distribution of costs
between mobile devices according to their performance capabilities. Our
protocols are based on elliptic curve cryptography (ECC) to achieve
computation and communication efficiency.


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Nächste Termine im Jahre 2005 - Next talks in the Year 2005


19.12.2005  Thomas Dullien.  Title TBA.

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Organisation:
Prof. Dr. Roberto Avanzi
Faculty for Mathematics
Ruhr-University Bochum
44780 Bochum, Germany

URL:   http://www.cits.rub.de
         http://www.rub.de/hgi