In a mobile ad hoc network, a source node must rely on intermediate nodes to forward its packets along multi-hop routes to the destination node. The performance of a mobile ad hoc network is closely related to the capability of the implemented routing protocol to adapt itself to unpredictable changes of topology network and link status. One of these routing protocols is optimized link state routing protocol which assumes that all nodes are trusted. However, in a hostile environment, the OLSR is known to be vulnerable to various kinds of malicious attacks. Without having any control on packet forwarding, an intermediate node can behave selfishly or maliciously to drop packets going through it. Therefore, in this article, the authors propose a new technique for the selection of multipoint relays whose aims to provide each node the ability to select alternative paths in order to reach any destination two hops away.