Abstract: Dissimilar to traditional networks, the features of mobilewireless devices that can actively form a network without anyinfrastructure mean that mobile ad hoc networks frequently displaypartition due to node mobility or link failures. These indicate that anad hoc network is difficult to provide on-line access to a trustedauthority server. Therefore, applying traditional Public KeyInfrastructure (PKI) security framework to mobile ad hoc networks willcause insecurities. This study proposes a scalable and elastic keymanagement scheme integrated into Cluster Based Secure Routing Protocol(CBSRP) to enhance security and non-repudiation of routingauthentication, and introduces an ID-Based internal routingauthentication scheme to enhance the routing performance in an internalcluster. Additionally, a method of performing routing authenticationbetween internal and external clusters, as well as inter-clusterrouting authentication, is developed. The proposed cluster-based keymanagement scheme distributes trust to an aggregation of cluster headsusing a threshold scheme faculty, provides Certificate Authority (CA)with a fault tolerance mechanism to prevent a single point ofcompromise or failure, and saves CA large repositories from maintainingmember certificates, making ad hoc networks robust to maliciousbehaviors and suitable for numerous mobile devices.