A localized trust management scheme for ad hoc networks

Wireless ad hoc networks are generating much interest, both in research literature and the telecommunication industry. The attractiveness of these networks lies in the fact that unlike other wireless networks, ad hoc networks are selfcontaining: the hosts constituting the networks can communicate with each other without reliance on centralized or specialized entities such as base stations. As these networks become more prominent, the need for adequate security mechanisms is increasingly apparent. Trust management is essential to the security framework of any network. In most traditional networks–both wired and wireless– centralized entities play pivotal roles in trust management. There are no centralized entities in ad hoc networks. This unique feature of ad hoc networks add many challenges in addressing this fundamental security issue: trust management. In this paper we present a trust management scheme that is based on the more reliable and structured hierarchical trust model. Our scheme is robust against malicious accusation exploits; it addresses explicit revocation of certificates without any input from centralized authorities, and it does so in such a way that the window of opportunity whereby revoked certificates can be accepted as valid, is practically eliminated.