A novel approach for the fast detection of black holes in mobile ad hoc networks.

Mobile ad hoc networks are infrastructure-less wireless networks that rely on node cooperation to properly work. In this kind of networks, attack detection and reaction is a key issue to the whole network. The most common threat in mobile ad hoc network scenarios consists in the presence of a certain percentage of selfish nodes, which try to reduce the consumption of their own resources to prolong their battery lifetime. Those nodes do not collaborate on forwarding activities, therefore affecting the overall network performance. Watchdogs are well-known mechanisms to detect threats and attacks from misbehaved and selfish nodes in computer networks. The problem behind the use of watchdogs is that while they can be quite effective in detecting selfishness by using their traffic overhearing behaviour, they can also cause a relatively high level of false negatives, thereby reducing their accuracy. This article proposes a collaborative approach for detecting selfish nodes in mobile ad hoc networks. It is based on using a set of collaborative watchdogs, which collaborate to enhance their individual and collective performance. By using both an analytical study and simulation, we demonstrate that our approach is able to improve accuracy and detection speed, while reducing the impact of false-negative events.