Secure and efficient cache-based authentication scheme for vehicular ad-hoc networks

Due to the emerging Vehicular Ad-hoc Network (VANET), real-time applications have come into existence nowadays. However, because of the wireless environment used in VANET, ensuring vehicle user (V-i) authentication and securing the communication against various active and passive attacks are essential. Traditionally, such challenges have been addressed with the help of a Trusted Authority (TA). Each time Roadside Unit (RSU) needs to authenticate V-i (newly/previously visited), it has to communicate with TA. We believe that this kind of arrangement will lead to unnecessary computation and communication overheads. This article introduces a secure and efficient cache-based authentication scheme for vehicular ad-hoc networks. Our proposed scheme utilizes Elliptic Curve Cryptography and divided into two different phases. The first phase (cache miss) deals with caching of identities (pseudonyms) of newly visited V-i into at RSU. During this process RSU authenticates such V-i through TA. The second phase (cache hit) deals with authentication of any previously visited V-i based on the RSU's cache entries (without communicating with TA). Due to this arrangement, the proposed protocol requires relatively less authentication delay as compare to the traditional authentication schemes without affecting desired security and design properties. Additionally, the performance analysis section shows that our protocol may be considered for low-power practical applications of VANET due to its enhanced security and reduced computation and communication overheads.