Mobile ad hoc network (MANET) has been generally regarded as an ideal network model for group communications because of its specialty of instant establishment. However, the security of MANET is still a challenge issue. Although there are some existing security schemes such as ARAN (Authenticated Routing for Ad hoc Networks) protocol that makes use of cryptographic certificate to provide end-to-end authentication during routing phases, the overhead of security computation is still a serious hurdle for real application. In this paper, we propose a comparatively efficient scheme to perform ARAN protocol, based on AODV, by using one-time signature in place of conventional signature, aiming at achieving the same level of security but improved efficiency. We also provide two approaches to handle the authentication of gratuitous route reply using delegation token and transitive signature schemes.