Vehicular ad hoc networks (VANETs) adopt the public Key Infrastructure (PKI) and certificates Revocation Lists (CRLs) for his or her protection. In any PKI system, the authentication of a obtained message is performed by checking if the certificate of the sender is included inside the modern CRL, and verifying the authenticity of the certificate and signature of the sender. On this project, we recommend an Expedite Message Authentication Protocol (EMAP) for VANETs, which replaces the time-consuming CRL checking process via an efficient revocation checking method. The revocation check process in EMAP uses a keyed Hash Message Authentication Code (HMAC), wherein the key utilized in calculating the HMAC is shared best between nonrevoked On-Board units (OBUs). similarly, EMAP uses a singular probabilistic key distribution, which permits nonrevoked OBUs to soundly share and update a secret key. EMAP can notably decrease the message loss ratio because of the message verification delay compared with the traditional authentication strategies employing CRL. By accomplishing safety evaluation and overall performance assessment, EMAP is established to be secure and efficient.