Security through Collaboration in MANETs

It is well understood that Mobile Ad Hoc Networks (MANETs) are extremely susceptible to a variety of attacks, and traditional security mechanisms do not work well. Many security schemes have been proposed that depend on cooperation amongst the nodes in a MANET for identifying nodes that are exhibiting malicious behavior such as packet dropping, packet modification, and packet misrouting. We argue that in general, this problem can be viewed as an instance of detecting nodes whose behavior is an outlier when compared to others. In this paper, we propose a collaborative outlier detection algorithm for MANETs that factors in a nodes reputation. The algorithm leads to a common outlier view amongst distributed nodes with a limited communication overhead. Simulation results demonstrate that the proposed algorithm is efficient and accurate.