SSRG International Journals
VANET (Vehicular Ad hoc NETwork) is a subclass of MANET in which each vehicle acts as a node. In VANET Road Side Units (RSUs) are responsible for distributing group private keys and managing vehicles in a localized manner for every 100 to 300 m. Then, use a Hash Message Authentication Code (HMAC) to avoid time consuming CRL checking and to ensure the integrity of messages. Cooperative message authentication scheme is mainly used for reducing the authentication burden. The scheme is more efficient in terms of authentication speed and privacy.