An Identity-based Conditional Privacy-Preserving Authentication Scheme with Key Protection for VANETs

Vehicular ad-hoc networks (VANETs) are widely used in transportation. After authenticating each other's iden-tities, users in VANETs can exchange data with one another, this process is also known as Vehicle-to-Vehicle (V2V) authen-tication. But being an open network, they need to meet some security and privacy requirements to be able to run steadily. Conditional Privacy-Preserving Authentication (CPPA) schemes are used to address the issues of unprotected user identities and some common attacks, such as impersonation and modification. However, these schemes rely on Tamper-proof Devices (TPDs) which are vulnerable to side-channel attacks. These attacks use the physical changes of TPDs during cryptographic operations to extract secret information. To overcome the drawback, we developed a V2V authentication scheme with key protection, which was implemented by splitting the private key into one encrypted part and another temporarily generated part. Without the knowledge of these two parts, there is no way to recover the private key even if TPD is attacked, thus ensuring the safety of the private key. Our proposed scheme can meet the requirements of V2V authentication and resist common attacks through security analysis. Moreover, from performance analysis, we have success-fully achieved a balance in performance compared to previous research” and our scheme is suitable for VANETs.