Every system seeks one thing, and that is Security. As MANET is mainly fraught with security challenges, the solutions involve two approaches. One is proactive and the other is reactive. The proactive approach attempts to thwart threats through cryptographic techniques while the reactive approach seeks to detect threats and act accordingly. For example, most secure routing protocols adopt a proactive approach to secure routing messages while the reactive approach is used for protecting packet forwarding operations.
In the ideal scenario, both approaches should be applied as per the requirement. These approaches need to incorporate prevention, detection, and reaction.
When it comes to prevention, it is said that deterring the attacker has been infeasible when it comes to MANET as mobile devices are prone to compromise or physical sturdiness. Therefore, the detection and reaction component work for occasional intrusions.
In MANET, the prevention component is mainly achieved by secure ad-hoc routing protocols that prevent the attacker from installing incorrect routing states at other nodes.
Ad Hoc Protocols such as DSR (2), AODV (1), and Destination-Sequenced Distance Vector (DSDV), and employ different cryptographic primitives for example, HMAC, digital signatures, hash chains) are used to authenticate the routing messages.
The detection part identifies abnormal behaviour by malicious nodes. Such a thing is observed in an end-to-end manner or by neighboring nodes through overhearing.
Once the detection is identified, the reaction component sees adjustments in routing and forwarding operation, ranging from avoiding the node in route selection to collectively excluding the node from the network.