On MAC-layer denial of service attacks in IEEE 802.11 ad hoc networks: analysis and counter measures

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 MAC-layer 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. To counter the first attacks, we propose a packet-by-packet authentication scheme so that legitimate nodes can reject data transmission requests from unauthenticated adversaries. To mitigate the second attacks, we propose several counter measures such as a fair MAC protocol, using protecting traffic flows and distance adjustment. The contribution of this paper is that it reveals the attacks that could be launched by an average person, which is a potential threat to MANETs.