Abstract: In Mobile Ad Hoc Networks (MANETS), Clustering based routing protocol can sufficiently enhance Performance, Scalability and Energy Efficiency. In this research Improved weight based clustering techniques integrated along with a routing protocol is proposed. Our approach is inspired from bird flocking behavior where birds travel long distances in flocks and conserve energy by constantly changing the leader of the flock. We have mainly concentrated on clustering algorithm and designed our clustering algorithm based on moment-to moment decisions of individual nodes during communication. In this protocol, the network is divided into chunks of nodes known as clusters. The clusters are actively maintained and reassembled using specific algorithms and techniques. Due to nature of inconstant wireless medium data transfer is a major problem in ad hoc it lacks security and reliability of data. Cryptographic techniques are often used for secure data transmission wireless networks. Most cryptographic technique can be symmetric and asymmetric, depending on the way they use keys. However, all cryptographic techniques is good for nothing if key management is weak. There is various type of key management schemes that have been proposed for ad hoc. Peer-to-peer computing is a popular paradigm for different applications that allow direct message passing among peers. The existing P2P search algorithms in MANET (Mobile Ad-hoc Network) are flooding-based search that produces much traffic and network overhead. File searching efficiency of peer-to-peer (P2P) network mainly depends on the reduction of message overhead. The research work deals with a full form of cluster based P2P file searching approach for MANETs, which focuses mainly over reduction of control messages. For searching, our mechanism uses cluster head within the cluster but it also allows inter-cluster communication. Moreover, secondary cluster head concept of our proposal ensures lower message overhead during cluster formation stage. Our clustering scheme utilizes request suppression to reduce the number of responses for searching process. Consideration of alternative paths to a node facilitates to overcome link failure. The improved weight based routing scheme is a position based routing approach which incorporates dynamic selection of the gateway nodes to reduce the number of control packets flooded in the network. The improved weight based clustering key management techniques increase the packet delivery ratio, reduce overhead and also reduces energy consumption in the network. The simulation study of proposed improved weight based clustering algorithm achieved better performance than the existing key management schemes. In this research overhead is reduced by 17%, energy consumption is reduced by 5% and packet delivery ratio is dramatically increased by 10%. Overall study of this research work achieves better performance compared with existing methods. This research work compares the efficiency of the proposed scheme with the existing schemes and the comparison shows that the proposed scheme performs better than the existing schemes in terms of reduction in key update messages.

Keywords: MANETS, Clustering Techniques, Routing protocol and Key Management