Abstract: | Vehicular Adhoc Network (VANET) is based on the principles of Mobile Adhoc NETwork (MANET) where vehicles are considered as nodes and secure communication is established to provide a safe driving experience. Due to its unique characteristics, it has various issues and challenges. These issues can be resolved by ensuring security requirements like authentication, privacy preservation, message integrity, non-repudiation, linkability, availability etc. Authentication plays a vital role since it is the first step to establish secure communication in the vehicular network. It also distinguishes malicious vehicles from legitimate vehicles. Different authentication schemes have been proposed to establish secure vehicular communications. A survey of the existing authentication schemes is given in this paper. At first, the existing authentication schemes are broadly classified based on message signing and verification methods. Then, each category is clearly explained with its sub-categories. At last, the existing schemes in each category are compared based on security requirements, security attacks and performance parameters. |