Existing security and identity-based vehicular communication protocols used in Vehicular Ad-hoc Networks (VANETs) to achieve conditional privacy-preserving mostly rely on an ideal hardware device called tamper-proof device (TPD) equipped in vehicles. Achieving fast authentication during the message verification process is usually challenging in such strategies and further they suffer performance constraints from resulting overheads. To address such challenges, this paper proposes a novel Chinese remainder theorem (CRT)-based conditional privacy-preserving authentication scheme for securing vehicular authentication. The proposed protocol only requires realistic TPDs, and eliminates the need for pre-loading the master key onto the vehicle's TPDs. Chinese remainder theorem can dynamically assist the trusted authorities (TAs) whilst generating and broadcasting new group keys to the vehicles in the network. The proposed scheme solves the leakage problem during side channel attacks, and ensures higher level of security for the entire system. In addition, the proposed scheme avoids using the bilinear pairing operation and map-to-point hash operation during the authentication process, which helps achieving faster verification even under increasing number of signature. Moreover, the security analysis shows that our proposed scheme is secure under the random oracle model and the performance analysis shows that our proposed scheme is efficient in reducing computation and communication overheads.

Vehicular ad-hoc networks (VANETs) have been emerging based on the state-of-art technologies in wireless and network communications. The message authentications between vehicles and roadside units are essential for the security of VANETs. Messages should be signed and verified before they could be trusted. The real identity of vehicles should not be revealed, but which is only traceable by authorized parties. Existing solutions either rely heavily on a tamper-proof hardware device or cannot satisfy the security requirement. Communication overhead as another issue has also not been well addressed in previously reported studies. To address these issues, in this paper, we propose the SPACF scheme that is based on software without relying on any special hardware. We use the Cuckoo filter and the binary search methods to achieve higher success rate than the previous schemes in the batch verification phase. In order to guarantee that it can satisfy message authentication requirement, existential unforgeability of underlying signature against adaptively chosen-message attack is proved under the elliptic curve discrete logarithm problem in the random oracle model. The evaluation results show that our proposed scheme is more efficient than the previous schemes since it is pairing free and does not use map-to-point hash functions, and it satisfies security and privacy requirements of vehicular ad hoc networks.

With the progress in wireless communication technology and the increasing number of vehicles, vehicular ad hoc networks (VANETs) have become essential for improving road conditions and enhancing driving experience. The core of the VANETs is the communication between different vehicles, and the security of the communication is based on message authentication. Several schemes have been designed to enhance the efficiency of message authentication. However, these schemes have the disadvantage of redundant authentication, i.e., repeated authentication of the same message, and fail to seek invalid messages from the batch of messages. To solve these problems, this paper introduces a novel edge-computing concept into the message-authentication process of VANETs. In our scheme, the roadside unit can efficiently authenticate messages from nearby vehicles and broadcast the authentication results to the vehicles within its communication range, thereby reducing redundant authentication and enhancing the efficiency of the entire system. The security analysis results show that the proposed scheme satisfies the security requirements of the VANETs. The performance analysis results show that the proposed scheme can not only work well in an ideal environment where the attacker is absent but also capable of quickly identifying valid and invalid messages even if the VANET is attacked.

With the advancements in social media and rising demand for real traffic information, the data shared in vehicular ad hoc networks (VANETs) indicate that the size and amount of requested data will continue increasing. Vehicles in the same area often have similar data downloading requests. If we ignore the common requests, the resource allocation efficiency of the VANET system will be quite low. Motivated by this fact, we propose an efficient and privacy-preserving data downloading scheme for VANETs, based on the edge computing concept. In the proposed scheme, a roadside unit (RSU) can find the popular data by analyzing the encrypted requests sent from nearby vehicles without having to sacrifice the privacy of their download requests. Further, the RSU caches the popular data in nearby qualified vehicles called edge computing vehicles (ECVs). If a vehicle wishes to download the popular data, it can download it directly from the nearby ECVs. This method increases the downloading efficiency of the system. The security analysis results show that the proposed scheme can resist multiple security attacks. The performance analysis results demonstrate that our scheme has reasonable computation and communication overhead. Finally, the OMNeT++ simulation results indicate that our scheme has good network performance.