Description

Wireless network dynamically allocates channel resources to improve spectral efficiency and, to avoid collisions, has its users cooperate with each other using a medium access control (MAC) protocol. However, MAC assumes user compliance and can be detrimental when a user misbehaves. An attacker who compromised the network can launch more devastating denial-of-service (DoS) attacks than a network outsider by sending excessive reservation requests to waste bandwidth, by listening to the control messages and conducting power-efficient jamming, by falsifying information to manipulate the network control, and so on. We build SecureMAC to defend against such insider threats while retaining the benefits of coordination between the cooperative users. SecureMAC is comprised of four components: channelization to prevent excessive reservations, randomization to thwart reactive targeted jamming, coordination to counter control-message aware jamming and resolve overreserved and under-reserved spectrum, and power attribution to determine each node’s contribution to the received power. Our theoretical analyses and implementation evaluations demonstrate superior performance over previous approaches, which either ignore security issues or give up the benefit of cooperation when under attack by disabling user coordination (such as the Nash equilibrium of continuous wideband transmission). In realistic scenarios, our SecureMAC implementation outperforms such schemes by 76%-159%.