IJSTE - International Journal of Science Technology & Engineering | Volume 1 | Issue 9 | March 2015 ISSN (online): 2349-784X All rights reserved by www.ijste.org 46 An Efficient Combined Cryptographic Approaches for Security Enhancement in MANET S. Chandra Kumar A. Alan Selva Denis PG Student PG Student Department of Computer Science & Engineering Department of Computer Science & Engineering Francis Xavier Engineering College, Tirunelevli Francis Xavier Engineering College, Tirunelevli P. Muthu Priya M. Iswarya PG Student PG Student Department of Computer Science & Engineering Department of Computer Science & Engineering Francis Xavier Engineering College, Tirunelevli Francis Xavier Engineering College, Tirunelevli Abstract The Communication systems are typical data systems, which can be undetermined by unauthorized users who have illegal access to the systems. Main Problem created in attacking to malicious node and group of network, whole traffic by system break, data loss, data affecting and data failure system. Overcome node Proposed scheme uses a role-based access control frame work, MANET concept working algorithm with combined cryptographic primitives. A cryptographic puzzle module and a SHA2 key- based module to protect traffic patterns transferred through the Mobile ad-hoc network. Source node sends the data packet through the wireless channel with these two combined cryptographic primitives. A node which wants to receive the traffic pattern must solve these two primitives. First it solves the cryptographic puzzles and then it solves the key-based scheme (symmetric encryption) then only it can access the data traffic pattern packet send over the Mobile ad-hoc network. This scheme is compatible with packet transmission and storage and it takes low power consumption. Our experiments have demonstrated that combines the cryptographic primitives for key based and Puzzle based techniques to provide better security, since it uses the double-guarded security so that it provides efficient and secured system for Mobile ad-hoc Network. Keywords: Attacker, DSA, sha-2, Merkle’s puzzles scheme ________________________________________________________________________________________________________ I. INTRODUCTION Network Security: A. Network Security (2,3) It is lack of trust, privacy, security, and reliableness impedes data sharing among distributed entities. Analysis is needed for the creation of information and learning in secure networking, systems, and applications. Change the preparation of secure applications within the pervasive computing and communication environments. Wireless Sensor Network (WSN): 1) Wireless Sensor Network (WSN) (3,4,8) It is spiffed a small network and data ad hoc network. It is a group of spatially dispersed and dedicated sensors for monitoring work. The physical conditions of the environment and organizing the node sending and receiving data are collected shared distributed network. WSNs measure environmental conditions packet loss for natural challenges for temperature, sound, pollution levels, humidity, wind speed and direction, pressure. Normal human affect for attacker. Overcome security provider whole network. It is a Security considerations can be security measures and cryptographic puzzle schema. Many protocols are using security purpose on WSN. This is paper using for Ad hoc On-Demand Distance Vector Routing (AODV) protocol in wireless sensor networks. Wireless Sensor Networks (WSNs) are composed of little, low cost, resource-constrained devices that sense the environment and cooperate with each other in order to perform monitoring and tracking operations. It may run critical applications, like military security and medical monitoring system and need to be protected against attacks and faults. a) Main Focus: The network infrastructure of a WSN is made up of small, low cost nodes spread over a possibly hostile area. Unlike other types of networks, it is often impossible to prevent the sensor nodes from being physically accessed by attackers. This is also referred to as node capture. It is reasonable to assume that an attacker can achieve full control over a captured node that is he can read its