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 a nd MAC layers in 802.11 based ad hoc networks. Collisions in wirel ess networks occur due to varying factors such as jamming attack s, hidden terminal interferences and network congestion. We p resent a probabilistic analysis to show that collision occur rence alone cannot be used to conclusively determine jamming attacks i n wireless channel. To increase the reliability of attack dete ction, it is necessary to provide enhanced detection mechanisms that can determine the actual cause of channel collisions. T o address this, we first investigate the problem of diagnosing the pres ence of jamming in ad hoc networks. We then evaluate the detection mechanism using cross-layer information obtained from physica l and link layers to differentiate between jamming and congest ed network scenarios. By correlating the cross-layer data with collision detection metrics, we can distinguish attack scenar ios from the impact of traffic load on network behavior. Through simulation results we demonstrate the effectiveness of our sch eme in detecting jamming with improved precision.