The central focus of this dissertation is mobile ad hoc networks (MANETs) and their security.
MANETs are autonomous networks of wireless nodes connected in an ad hoc manner, and have
unique characteristics that make them difficult to secure. The principal aims of this
investigation are to discuss the research and evaluation of existing mechanisms to secure
MANETs and to design the implementation of a unique security mechanism. Key management
is a major challenge in these networks due to the lack of fixed network infrastructure. In
presenting a survey of the existing key management solutions for MANETs, the findings
indicate that most security attacks target the network layer and more specifically the routing
protocol. Consequently, the provision of secure routes is a vital element for trust establishment,
and accordingly a survey is provided of the existing secure ad hoc routing protocols. The
observation is made that most secure ad hoc routing protocols assume the existence of a key
management system to certify, authenticate, and distribute keying information. Mobile ad hoc
networks cannot assume the existence of a centralized authority member to perform key
management tasks, and the problem of key management must be addressed.
A novel key management solution called Direct Indirect Trust Distribution (DITD) is proposed
for an on-demand ad hoc routing protocol. The solution includes a trust evaluation mechanism
and a key distribution scheme to distribute keying information in the form of certificates. The
key distribution scheme performs localized certificate exchanges following the routing
procedure. A security evaluation metric is proposed that aggregates trust along a path based on
a security metric and the path distance. The proposed solution is implemented on a modified
AODV routing protocol, and simulated on the ns2 Network Simulator. Simulations are
conducted in order to compare the performance of the AODV and DITD protocols. The
simulation results show that the DITD model provides key distribution and trust path selection
with minimal effect on the routing agent. The findings of the investigation confirm that DITD
can be used as a basis for the operation of existing security protocols requiring a secure key
distribution mechanism. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2010.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ukzn/oai:http://researchspace.ukzn.ac.za:10413/2850 |
| Date | January 2010 |
| Contributors | Dawoud, D S |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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