Mobile Ad hoc Network (MANET) consists of some nodes, which are randomly placed in operational environment. This type of network does not have any infrastructure and nodes are completely dynamic and moveable. Each node can contact with the other in-range nodes. One of the disadvantages of MANET is the low lifetime of nodes power in which the energy consumption of the network goes up due to connectivity overheads. In this paper, by presenting a Fuzzy clustering algorithm, we endeavor for a more optimized energy consumption of this network by reducing the number of re-election of clusterheads (CHs) and reducing the re-affiliation of nodes and also by selecting the best node as CH amongst current members of each cluster. The result of simulation shows that our algorithm performs better than other existing algorithm.

In mobile ad hoc network (MANET), secure communication is more challenging task due to its fundamental characteristics like having less infrastructure, wireless link, distributed cooperation, dynamic topology, lack of association, resource constrained and physical vulnerability of node. In MANET, attacks can be broadly classified in two categories: routing attacks and data forwarding attacks. Any action not following rules of routing protocols belongs to routing attacks. The main objective of routing attacks is to disrupt normal functioning of network by advertising false routing updates. On the other hand, data forwarding attacks include actions such as modification or dropping data packet, which does not disrupt routing protocol. In this paper, we address the “Packet Drop Attack”, which is a serious threat to operational mobile ad hoc networks. The consequence of not forwarding other packets or dropping other packets prevents any kind of communication to be established in the network. Therefore, there is a need to address the packet dropping event takes higher priority for the mobile ad hoc networks to emerge and to operate, successfully. In this paper, we propose a method to secure ad hoc on-demand distance vector (AODV) routing protocol. The proposed method provides security for routing packets where the malicious node acts as a black-hole and drops packets. In this method, the collaboration of a group of nodes is used to make accurate decisions. Validating received RREPs allows the source to select trusted path to its destination. The simulation results show that the proposed mechanism is able to detect any number of attackers.