Abstract: The open nature of wireless medium makes it vulnerable to intentional interference attacks, which are typically referred to as jamming. This intentional interference with wireless transmissions can be used as a launching pad for mounting denial of service attacks in wireless networks. Usually, the interference has been addressed in one form of external threat. However, adversaries with inner knowledge of protocol specifications and network secrets can launch low-effort jamming attacks that are difficult to detect and counter. In this paper the problem of selective jamming attacks in wireless networks are addressed. In these attacks, the adversary is active only during a short period of time, selectively targeting messages of high importance. We illustrate the advantages of selective blockade in terms of degradation of network performance and adversary effort by presenting two case studies; a selective attack on TCP and one in the routing. We show that selective jamming attacks can be initiated by performing packet classification in real time at the physical layer. To mitigate these attacks, two schemes which prevent the classification of packets in real time by combining the cryptographic primitives physical layer attributes are developed. The security of our method is analyzed and evaluated its computational overhead and communication.
Keywords: Selective Jamming, Denial-of-Service, Wireless Networks, Packet Classification.