Nowadays, Mobile Ad-Hoc Network (MANET) because of the quick and easy setup, reducing the cost and facilitating the communication, except of specific applications can also used widely in other areas. Basic routing protocols establish based totally on assuming of secure wireless channel, honesty of nodes and cooperation of trustable and unselfish nodes. But Actually MANETs faces many challenges, in security and energy management domain due to lack of any centralized infrastructure, Distributed architecture and dynamic nature. However, due to the specific uses of these networks in high-risk environments, such as military environment, emergency operations, it is critical to ensure from security and proper functioning of the network. Thus, over the past few decades, researchers have tried to overcome the various challenges in these networks via two approaches including preventive and detective one. In preventive approach diffrent secure protocols have been proposed cryphtographic mechanisms. In detective approach many mechanisms have been introduced that the most important one is intrusion detection systems. In this work, by choosing one of the most common routing protocols, AODV, we evaluate the performance of prevention/detection mechanisms. In order to enhance the intrusion detection on MANET we proposed a hierarchical Intrusion Detection Systems. Implementation of the proposed architecture improves anomaly detection rate compared to other architectures. We use the advantage of the proposed hierarchical architecture to identify the attacker nodes. Proposed hierarchical architecture can reduces the cost of implementing intrusion detection and allowing us to provide a model for optimize energy consumption in MANET. Finally, in order to employ the advantages of a prevention-detection mechanism, the proposed architecture was implemented on SAODV that was achieved the better security level in this case too. Keywords: Mobile Ad hoc Network (MANET), AODV, Intrusion Detection System, Cryptography, hierarchical Intrusion Detection Systems, Energy Management
