A Mobile Ad hoc Network (MANET) is a set of wireless mobile nodes form a network devoid of using any obtainable infrastructure. MANET is a set of mobile nodes equipped with both a wireless-transmitter and receiver that communicate with each other via bi-directional wireless links either directly or indirectly. In MANET (mobile ad-hoc network), leader election takes place in the presence of selfish nodes for intrusion detection. In order to balance the resources in the nodes the nodes having the more weightage is being elected as the leader. There exist two obstacles to achieve this goal. Without any incentive being allocated, the node lies about its resources and acts selfishly by avoiding itself not being elected. Second, electing an optimal collection of leaders to minimize the overall resource consumption may incur a prohibitive performance overhead. Similarly intrusion detection system (IDS) plays major role for controlling malicious activity in the mobile ad-hoc network. Therefore assigning IDS to each and every node is time consuming process and the overall lifetime of IDS in MANET gets reduced. The efficient mechanism design approach been used in leader election based IDS to detect the malicious activities of mobile nodes and this system also leads a solution for reputation based secured communication in trusted mobile adhoc networks.