The ad hoc network (or MANET, for Mobile Ad hoc NETwork) is a system containing a set of devices that organize themselves, thus forming an autonomous and dynamic network, communicating via radio interface. These devices can be fixed or mobile, no wired infrastructure is available, and so these objects have to dynamically discover their environment.The design of these applications is based on trust between the nodes constituting the network. Unfortunately, when deploying randomly in difficult hostile areas, seeing impossible to monitor, not to mention the uncertainty of the communication channel, the sensor nodes are exposed to all types of attacks and intrusions, which can hinder and prevent the diffusion of the information between the sensor nodes of the network, and influencing its performance.Many approaches have been proposed to solve security problems in wireless networks. The solutions can be mainly classified into two categories: symmetric and asymmetric key management schemes. Indeed it is clear, that the optimal solution in this case is to use symmetric shared key systems.In this paper, the idea of LEAP improved is to apply the same Mechanisms used in LEAP Enhanced to overcome a compromised node and also prevent a compromised base station node while using a multiple base station network, this will, on the one hand, minimize power consumption, and secondly, to replace a base station in the event of a compromise, to ensure the continuity and proper functioning of the network. The evaluation of the proposed solution was carried out using the TOSSIM simulation tool.