A vehicular ad hoc network (VANET) allows for vehicles on roads to form a self-organized network and broadcast messages among them. However, as data are transmitted in an insecure network, it is essential to use an authentication mechanism to protect the privacy of vehicle users. Recently, Ying et al. proposed an authentication protocol for secure vehicular networks and claimed that the protocol could resist various attacks. Unfortunately, we discovered that their protocol suffered from an offline identity guessing attack, location spoofing attack, and replay attack, and consumed a considerable amount of time for authentication. To resolve these shortcomings, we propose an improved protocol. In addition, we provide a formal proof to the proposed protocol to demonstrate that our protocol is indeed secure. Compared with previous methods, the proposed protocol performs better in terms of security and performance.

Fog computing architecture is used in various environments such as smart manufacturing, vehicular ad hoc networks. However, as an extension of cloud computing, inheriting security challenges of cloud computing is inevitable. Recently, Jia et al. proposed an authenticated key exchange scheme for fog-driven IoT health care systems. Unfortunately, we discovered their scheme is vulnerable to an ephemeral secret leakage attack. In this paper, we propose an authenticated key exchange scheme for fog computing. Compared with previous schemes, our proposed scheme performs better in terms of performance and security.

The fifth-generation (5G) mobile communication technology with higher capacity and data rate, ultra-low device to device (D2D) latency, and massive device connectivity will greatly promote the development of vehicular ad hoc networks (VANETs). Meantime, new challenges such as security, privacy and efficiency are raised. In this article, a hybrid D2D message authentication (HDMA) scheme is proposed for 5G-enabled VANETs, in which a novel group signature-based algorithm is used for mutual authentication between vehicle to vehicle (V2V) communication. In addition, a pre-computed lookup table is adopted to reduce the computation overhead of modular exponentiation operation. Security analysis shows that HDMA is robust to resist various security attacks, and performance analysis also points out that, the authentication overhead of HDMA is more efficient than some traditional schemes with the help of the pre-computed lookup table in V2V and vehicle to infrastructure (V2I) communication.