Link layer security for SAHN protocols

Wireless networks are at risk of security attacks since transmissions can be intercepted by anyone within the transmission range. Therefore participating entities should incorporate robust systems to withstand the attacks as rigorously as possible. In this paper we present a link level security protocol (LLSP) to be deployed in a suburban ad-hoc network (SAHN) (Pose and Kopp, 1998). A SAHN aims to provide suburban area connectivity for local area networks at broadband speed with a low initial cost and zero service charges using wireless technology. LLSP provides services for authentication, integrity assurance, encryption and detection of misbehaving neighbors to ensure security at the data link layer. We propose a design framework to integrate LLSP within existing MAC protocols (e.g. IEEE 802.11b) and estimate the computational and communication overhead of LLSP. Results show that LLSP´s overhead should not adversely affect the normal flow of traffic. Moreover, comparisons with existing solutions indicate that LLSP is a suitable link-level security service for an ad-hoc network similar to a SAHN.