In-depth evaluation of security requirements and attacks for secure data communication in ITS.

With new technology, the Intelligent Transportation System (ITS) has evolved into Data-Driven Intelligent Transport System (DDITS) and further to the Internet of Vehicles (IOV) during the last few decades. Vehicular Ad-hoc networks (VANETs), a hierarchy of Mobile Ad-hoc networks (MANETs), are usually deployed in smart ITS in urban, highway, and rural scenarios. VANET facilitates vehicle-to-everything (V2X) communication with massive exchanges of safety and non-safety messages to other vehicles. Moreover, it achieves low latency in an open-access environment without requiring fixed infrastructure or centralized administration, improving ride quality, safety, comfort, and efficiency issues in road traffic. However, open wireless communication channels make these messages vulnerable to attackers to intercept, tamper, replay, and eradicate them. Hence, this paper provides an extensive overview of VANETs, security, and various attacks and countermeasures. It further analyses the critical and challenging security issues, in particular Authentication, data confidentiality, data integrity, availability, and nonrepudiation. [ABSTRACT FROM AUTHOR]