We proposed a secure and efficient key management framework (SEKM) for MANETs. SEKM builds a PKI by applying a secret sharing scheme and using an underlying multicast server groups. In SEKM, each server group creates a view of the certificate authority (CA) and provides certificate update service for all nodes, including the servers themselves. Motivated by the distributed key management service, we introduced k-Anycast concept and proposed three k-anycast routing schemes for MANETs. k-anycast is proposed to deliver a packet to any threshold k members of a set of hosts. Our goal is to reduce the routing control messages and network delay to reach any k servers. The first scheme is called controlled flooding. The second scheme, called component-based scheme I, is to form multiple components such that each component has at least k members. The third scheme, called component-based scheme II, in which the membership a component maintains is relaxed to be less than k.