Abstract: Authentication in Mobile ad-hoc Networks (MANETs) is difficult and challenging because of its frequent topology changes. Central authority based authentication schemes have been proposed and with every movement of a node outside the network demands re-authentication of the nodes by the central authority before the node rejoins the network. This research contribution intends to propose a novel Non-Interactive Zero Knowledge Protocol (NIZKP) to address this problem of re-authentication. The proposed NIZKP achieves re-authentication by neighborhood authentication of the node that wants to rejoin the network. This reduces the dependences on the central authority for re-authentication thereby avoiding the attacks that are possible during re-authentication.