Three-factor authentication and key agreement protocol with collusion resistance in VANETs

In vehicular ad hoc networks (VANETs), vehicles possess the capability to interact efficiently with a diverse array of services and applications provided by edge vehicular infrastructures. Concurrently, the ongoing interactions among vehicles facilitate the real-time acquisition of crucial road information. However, these vehicular communications primarily occur over unsecured public channels, rendering confidential data susceptible to illegal access by malicious entities. To address this security concern, numerous cryptographic schemes, including the widespread adoption of multi-factor authentication techniques, have been introduced. Despite these efforts, the existing authentication methods are limited, as they solely focus on verifying the legitimacy of individual users, resulting in restricted functionality and diminished security capabilities. So, three-factor authentication and key agreement protocol with collusion resistance in VANETs (TFA-CR) in this paper is developed, which also ensures resistance against collusion attacks. In the proposed design, we leverage hybrid characteristics that encompass both vehicle and user attributes, such as user identity, user-defined parameters, and vehicular verification codes. These attributes are efficiently extracted and utilized throughout the subsequent authentication process, creating a distinctive authentication mechanism tailored for real-world multi-vehicle scenarios. This enables seamless network access for individual users across different vehicles using only a single smart card. A thorough performance evaluation reveals that the protocol effectively reduces both communication overhead and computational complexity when compared to existing authentication techniques.