Committee Chair

Yang, Li

Committee Member

Kizza, Joseph; Sartipi, Mina

Department

Dept. of Computer Science and Engineering

College

College of Engineering and Computer Science

Publisher

University of Tennessee at Chattanooga

Place of Publication

Chattanooga (Tenn.)

Abstract

Ad hoc networks are very helpful in situations when no fixed network infrastructure is available. They are especially important in emergency situations such as natural disasters and military conflicts. Most developed wireless ad hoc routing protocols are designed to discover and maintain an active path from source to destination with an assumption that every node is friendly and cooperative. However, it is possible that the participating nodes are selfish or malicious. A mechanism to evaluate reputation for each node is essential for the reliability and security of routing protocol in ad hoc networks. We propose a fine-grained reputation system for wireless ad hoc routing protocols based on constantly monitored and updated first and second-hand reputation information. The nodes in the network monitor their neighbors and obtain first-hand information based on the perceived behavior. Second-hand information is obtained by sharing first-hand information with nodes’ neighbors. Our system is able to distinguish between selfish and malicious nodes and take appropriate actions in either case. We employ the moving-window mechanism which enables us to assign more weight to more recent observations and adjust responsiveness of our reputation system to changes in nodes’ behavior. We show that our fine-grained reputation system is able to improve both reliability and security of an ad hoc network when compared to a reputation system that does not distinguish between selfish and malicious nodes.

Degree

M. S.; A thesis submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Master of Science.

Date

2008

Subject

Wireless communication systems

Discipline

Computer Sciences

Document Type

Masters theses

Extent

vii, 73 leaves

Language

English

Rights

Under copyright.

License

http://creativecommons.org/licenses/by-nc-nd/3.0/

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