A new group Diffie-Hellman key generation proposal for secure VANET communications

Vehicular Networks must be sufficiently secured against the wide variety of security challenges to which they are exposed. Cryptography provides tools to solve many of these security problems. In this paper, we address the secure group communications problem in VANETs. By generating a secret group key that can be used to encrypt or authenticate, the members of a VANET platoon can thus guarantee secure communication between them. To address this need, we propose a new secure variant of the Diffie-Hellman algorithm for groups that we fortified by a pre-shared secret to withstand the famous Man in the Middle attack. As necessary, our proposal can be used by several types of authentication and encryption VANET applications. We demonstrate the unforgeability and the privacy of our scheme and we study its secure-efficiency.