Scalable security schemes for ad hoc networks

Inherent characteristics of any ad hoc network such as dynamic topology and limited physical security poses severe security challenges to the network. Hence, these networks demand much stronger security mechanisms than the traditional networks. It is hard to achieve security and robustness in the routing protocols at the same time in such networks. Several issues have to be understood and addressed before devising a security mechanism. This paper targets securing the reactive routing protocol AODV. The routing protocol is vulnerable to two kinds of attack: external and internal attack. We have discussed some existing external attacks and possible malicious behavior from compromised nodes. To mitigate the attacks, we propose a dual level security model. On the first level, we have the external attack detection model (EADM), that secures the network with authentication and confidentiality that rely on mutual trust between nodes. And on the second level, the intrusion detection model (IDM) identifies the misbehaving nodes using the knowledge base and the response model (RM) isolates these nodes from the network.