Many trust establishment solutions in mobile ad hoc networks (MANETs) rely on public key certificates. Therefore, they should be accompanied by an efficient mechanism for certificate revocation and validation. In order to reduce the hazards from nodes and to enhance the security of network we propose to develop a CA distribution and a Trust based threshold revocation method. Initially the trust value is computed from the direct and indirect trust values. And the certificate authorities distributes the secret key to al the nodes. Followed by this a trust based threshold revocation method is computed. Here the misbehaving nodes are eliminated.