Enhanced security against internal attacks in MAODV routing protocol

In MANET, mobile nodes communicate with each other with the help of intermediate nodes if they are not in direct transmission range. Nodes in MANET uses decentralized routing mechanism for communication. Lack of centralized mechanism and mobile nature of nodes increases security threats in MANET. For proper communication, all nodes are supposed to be cooperative with each other and malicious nodes can take advantage of this to implement its attack. Internal attacks in MANET are more severe as malicious nodes in these attacks are assumed as cooperative nodes. In these kind of attacks malicious node behave normal to become part of network and then launches its attacks. Unicast security approaches cannot be directly applied to complex multicast routing making these kind of attacks a challenging task for multicast routing protocols. In multicast routing protocols where one or more senders communicates with multiple receivers, internal attacks can do more damage as compared to unicast. To deal with this, authors proposed trust based security mechanism for multicast ad hoc on demand distance vector routing (TMOADV) in this paper. Instead of only hop count, TMAODV uses weighted combination of hop count and trust of nodes to select the shortest trustworthy path for data packet transmission in MAODV. The performance analysis of TMAODV, MAODV and PUMA (Protocol for Unified Multicasting through Announcements) protocols is done using NS2 simulation. TMAODV shown better packet delivery ratio with less effect on latency and control overhead in presence of internal attacks.