A detection and prevention system against collaborative attacks in Mobile Ad hoc Networks

Mobile Ad hoc Networks (MANETs) are vulnerable to various kinds of threats due to their dynamic nature and lack of a central point of control. Collaborative attacks occur when multiple attackers synchronize their actions to disrupt a target network. A wormhole attack is one of the most severe collaborative attacks, as it can harm a network in several ways. Wormhole attacks are very difficult to detect, as they are launched by two or more nodes in collaboration with each other and they work in two phases. In the first phase, malicious nodes try to convince legitimate nodes to transfer data through them in order to get acces to more routes. In the second phase, malicious nodes exploit the received data in a variety of ways. In this paper, we propose a Detection and Prevention System (DPS) to detect and block malicious nodes in MANETs. For this purpose, special nodes called DPS nodes, which continuously monitor the behavior of other nodes, are deployed in a network. When a DPS node finds a node exhibiting pre-defined suspicious behavior, it declares that suspicious node as a wormhole node by broadcasting a message. All data and control messages from a node that has been declared as wormhole node are discarded by the network. NS-2 simulations show that the proposed DPS considerably reduces the number of packets dropped by malicious nodes with very low false positive rate.