Byzantine Attack Isolation in IEEE 802.11 Wireless Ad-Hoc Networks

This paper introduces an effective solution against Denial of Service (DoS) implemented by byzantine attack in a fully distributed ad-hoc wireless network employing IEEE 802.11. Byzantine attack is the attack performed by a fully trusted node that´s turned rogue and already has passed all the authentication and verification processes. When a trusted node is turned rogue, it can easily perform DoS attack on the media access control (MAC) layer to prevent other nodes from communicating. DoS attack is an easy and effective method to disrupt the communications. The byzantine attacker will alter the implementation of the IEEE 802.11 DCF standards to illegally increase the probability of having a successful packet transmitted into the channel on the expense of the other nodes that follow the protocol standards. The solution presented in this paper depends on three stages. First stage is to identify the attacker using mathematical modeling. The second stage utilizes asymmetric cryptography to allow the good nodes communicate to agree on communicating on another frequency and excluding the byzantine attacker, and finally the third stage where the good nodes change the frequency via controlling their transmitters and receivers. The theoretical throughput will be generated using two dimensional Markov Chain to determine the network capacity. Results obtained by the theoretical computations will be used to constantly monitor the network and identify an attacker if present. A cross layer technique will allow the MAC layer to control the Physical layer to change the frequency of the communication session based on the MAC´s decision of identifying an attacker.