Improving Reliability of Jamming Attack Detection in Ad hoc Networks

Defense against denial of service (DoS) attacks is a critical component of any security system as these attacks can affect the availability of a node or an entire network. In this work, we focus on jamming type DoS attacks at the physical and MAC layers in 802.11 based ad hoc networks. Collisions in wireless networks occur due to varying factors such as jamming attacks, hidden terminal interferences and network congestion. We present a probabilistic analysis to show that collision occurrence alone cannot be used to conclusively determine jamming attacks in wireless channel. To increase the reliability of attack detection, it is necessary to provide enhanced detection mechanisms that can determine the actual cause of channel collisions. To address this, we first investigate the problem of diagnosing the presence of jamming in ad hoc networks. We then evaluate the detection mechanism using cross-layer information obtained from physical and link layers to differentiate between jamming and congested network scenarios. By correlating the cross-layer data with collision detection metrics, we can distinguish attack scenarios from the impact of traffic load on network behavior. Through simulation results we demonstrate the effectiveness of our scheme in detecting jamming with improved precision.