Security threats to the MAC-layer in wireless networks

Abstract

Medium access control (MAC) protocol security is important in wireless networks due to the lack of physical access control that normally exists in wired networks in the form of connecting a cable. Most efforts in standards organizations and academic research focus on the requirements of confidentiality and authentication. These approaches to wireless MAC-layer security often ignore two other threats to security: attacks against availability and incorrect implementation of MAC protocol and driver routines. The former can prevent a user from communicating at all, whereas the latter can have consequences ranging from dropped packets to complete host compromise. This dissertation comprehensively investigates the threats against wireless MAC protocols: being uncooperative, denial-of-service (DoS), sniffing, man-in-the-middle (MITM), and fuzzing. I provide a mathematical model to understand how network parameters impact the uncooperative carrier-sense-misbehaving attackers. Next, this dissertation shows a novel DoS attack that targets queuing behavior of access points by exploiting some factors of the IEEE 802.11 MAC protocol. Further, I propose a scheme that establishes a wireless connection that is secure against sniffing and MITM between a client device and an access point in IEEE 802.11 hotspots. Finally, I propose MAC-layer threats including fuzzing in IEEE 802.16e mobile WiMAX networks.