Group key exchange protocol based on diffie hellman technique in Ad hoc Network

ABSTRACT: During last decade, wireless ad hoc networks have been widely used for communication, transferring data or sharing some information for specific members. Nowadays security protocols play a fundamental role to provide a level of security for wireless local area networks (WLAN). Moreover, one of the most important issues to improve security by help of cryptography algorithms is generating a common key among participants to intercommunicate securely. The aim of thesis is creating a common secret key by means of Diffie Hellman (DH) technique, so the contributory group key exchange protocol is established in order to perform efficiently in context of ad hoc. To this aim, some analysis on Biswas’s protocol (G. Biswas, IET Information Security, March 2008) and Tseng’s protocol (Y.-M. TSENG and T.-Y. WU, INFORMATICA International Journal, April 2010) are done. Tseng’s protocol fails to establish a common key in some situations, when the key generated by DH technique is not invertible. Thus, it is modified in order to fix the problem and achieve better performance in view of the computational cost for the proposed Tseng’s modified protocol. Furthermore, theoretical analysis shows that computational cost in Tseng’s modified protocol for each participant and the controller is decreased about 1.5 and 3 times in comparison with Tseng’s protocol respectively. Tseng modified protocol is implemented and is tested for ad hoc WLAN with 3, 4, and 5 nodes. Keywords: ad hoc, Wireless Local Area Network (WLAN), Network Security, Diffie Hellman Key Exchange (DH Key Exchange), Group Key Exchange (GKE), Tseng’s protocol. …………………………………………………………………………………………………………………………