The key distribution provides public and private key pairs to the vehicles and RSUs from the servers. The keys are used to maintain the safety and privacy level of VANET users. The key distribution is classified into static and dynamic. The static key distribution methods provide only one static key pair to the users, whereas the keys are periodically updated in dynamic key distribution models. The dynamic key distribution models are more efficient in the VANET environment, as it handles the dynamicity effectively. However, overhead is a major issue of key distribution methods.