The blockchain models assist the VANETs in solving the critical message dissemination issues with high security. The blockchain model is a distributed method that integrates Bitcoin cryptocurrency methods in which a sequence of immutable blocks are generated based on the historical transmissions. The VANETs exploit blockchain modes to evaluate and maintain the ground trustworthiness of vehicles. The blockchain models are divided into two types that are public and private. In the public blockchain model, any vehicle can access the blocks, whereas it is only revealed for authorized users in the private blockchain model.