A Secure Data Transfer and Effective Key Management Scheme for Vehicle Ad-Hoc Networks

Vehicle Ad-Hoc Networks (VANETs) have garnered significant academic interest due to the increasing demand for both safer driving solutions and in-vehicle entertainment systems. Ensuring robust information security within these networks is critical, given their potential impact on public safety. This work introduces a secure authentication framework that utilizes a hash chaining technique, where each vehicle iteratively applies a cryptographic hash function to its master key, generating a sequence of authentication codes that are both unique and tamper-resistant. Roadside Units (RSUs) serve as intermediaries, facilitating data exchange between vehicles and a centralized Authentication Authority (AA)—a trusted entity responsible for verifying vehicle identities. The hash chain mechanism accommodates the highly dynamic topology of VANETs, enabling vehicles to authenticate without continuous reliance on a central server. To further enhance security, a Dual Key Management Mechanism (DKMM) is proposed, involving two separate group keys: one dedicated to Trusted Authorities (TAs) and another for verified vehicles. Unlike conventional schemes that employ static keying materials, DKMM dynamically updates cryptographic keys in response to vehicular motion and changes in network topology. This dynamic strategy not only maintains high security levels in fast-moving environments but also reduces computational burden by limiting the frequency of hash computations. Furthermore, the integration of Elliptic Curve Cryptography (ECC) streamlines secure key exchanges while optimizing key revocation procedures. Although the scheme proves highly efficient, it also addresses practical challenges such as increased processing overhead in densely populated areas and the complexities of synchronizing keys across rapidly changing network configurations.