Analyzing and Preventing MAC-Layer Denial of Service Attacks for Stock 802 . 11 Systems

Network survivability is fundamental to information security. Adversaries could compromise network functionality by attacking the physical layer, the medium access control (MAC) layer, or the network layer. Even though security mechanisms for the network layer have been extensively discussed, MAC layer security has not been deeply explored. Leveraging security flaws in the IEEE 802.11 MAC protocol and the salient features of a Mobile Ad Hoc Network (MANET), even an average person with limited knowledge of wireless networks can launch MAClayer denial of service (DOS) attacks. In this paper, we study two types of MAC layer DOS attacks that can be easily employed by an average person: attacks launched from a single adversary by injecting enormous data flows into the network, and attacks launched from two colluding adversaries by sending enormous data flows directly to each other. We propose new counter measures to defend against these two types of DOS attacks. Since this paper focuses on MAC layer DOS attacks that could be easily executed by an average person, and compromising legitimate nodes is not an easy task, we only consider DOS attacks launched directly from adversaries, instead of from compromised nodes.