# Toward Collaborative Intelligence in IoV Systems: Recent Advances and Open Issues
## 3 Networking Technologies toward Collaborative Intelligence
### Authentication and Secure Communications in IoV  
More and more connected devices are joining the IoV. The comprehensive application of collaborative intelligence in the IoV requires a variety of devices to take part in the data collection, transmission, and calculation processes. This leaves the communication process between vehicles, users, Road Side Units (RSUs), and edge and cloud servers all exposed to network security attacks. This is a very serious problem because it involves a large range of traffic safety issues, and may endanger lives. For example, critical information such as traffic jams, traffic light information, accident reports, and the driving status of nearby vehicles may be intercepted and modified by malicious vehicles or operated RSUs, resulting in missing or incorrect information that can cause damage or accidents. Therefore, protecting the critical data communication in the network is a key link in IoV. In addition to data communication security, another important issue is user privacy protection. The recent studies in authentication and secure communications are listed in Table 3. There are many forms of attacks from all sides in the IoV. In article [56], 14 possible attacks on vehicular ad hoc networks are listed. These include Greedy Drivers, Impersonation Attack, Wormhole Attack, Pranksters, Blackhole Attack, and Denial of Service. Therefore, high requirements are put forward for the IoV system. A collaborative intelligent vehicle internet environment, from the perspective of privacy and security, must be able to [57]:  
* Achieve effective and fast authentication of the validity and integrity of messages. * Avoid exposing user privacy to anyone other than the licensor. * Trace the appearance of malicious nodes or false information in the network. * Ensure that the information transmitted by malicious nodes is irrelevant to the control of vehicles. * Withstand cryptanalysis attacks by quantum computers. * Prevent middleman modification, counterfeiting, authentication table theft, replay attacks, etc. Secure communication protocol has always been an active research field. With the development of IoT technology, security authentication protocols in IoV are also developing. In view of the above safety requirements, researchers have carried out many related studies recently. To solve the problems of vehicle identity privacy, distribution of certificate revocation Lists, and computing and communication constraints of vehicular devices intermittently connected to infrastructure, [PERSON] et al. [58] designed certificate-based batch authentication technology. However, the fast data communication between vehicles in such schemes and RSUs requires cumbersome certificates, and has a high key storage burden and a long operation time. In view of the user's computing power and the sensitive information contained in the access policy, [PERSON] et al. [59] designed an attribute-based ciphertext policy encryption technology for vehicle authentication, and supported information cancellation of vehicles that no longer shared data. In Ref. [60], a bidirectional authentication scheme based on decentralized key management is designed to automatically enroll, refresh, and withdraw the customer's public key. But these two methods are vulnerable to quantum attack. The IoV based on fog clouds is another variant of mobile cloud computing. There are many studies that try to combine fog computing with VANETs to satisfy the requirements for mobility and low latency in practical VANETs. [PERSON] et al. [61] proposed a novel protocol with authenticated key agreement and without bilinear pairing, which realized mutual authentication, generated session keys with security conventions for secret communication, and supported privacy protection. [PERSON] et al. [62] proposes one lightweight authenticating and key-managing scheme for IoV based on fog computing, which implements authentication key management between vehicle and fog server, RSU and fog server, and cloud server and fog server.