# Secure and Lightweight Cloud-Assisted Video Reporting Protocol over 5G-Enabled Vehicular Networks
## 1 Introduction  
Due to the merits of the fifth-generation (5G) cellular networks such as higher mobility support, massive connectivity and reduced latency [1], the academia and industry have shown interest in the 5G technology as a shifting paradigm which overcomes the limitations of the fourth generation (4G) technology. For example, leading companies in IT such as Cisco has predicted that the 5G cellular networks could meet the global mobile data traffic projections for the next five years [2]. That is, it is expected that the 5G cellular networks through the _massive connectivity_ property will enable the connection of millions of devices including vehicles. Especially, 5G cellular networks were embraced as the ultimate framework which would help the implementation of vehicular related technologies [3; 4; 5]. For example, a driverless vehicle was tested over 5G cellular networks by _Uber_ in the beginning of the year 2017 [6]. Let us note that vehicular network is still in its architectural stage regardless of considerable amount of research works available in the literature [7; 8; 9; 10]. Also, security and privacy threats, lack of scalability and latency due to the high mobility of the vehicles are considered as the main reasons that delay the real deployment of vehicular networks. In practice, the researchers have proved that even IEEE 802.11p lacks of mobilitysupport [7] and the Long Term Evolution (LTE) network does not support the effective latency for the vehicular networks [11; 12; 13]. Thus, the predicted performance of 5G cellular network in terms of latency, mobility and so on has been considered as a promising archetype for the practical implementation of the intelligent transportation system (ITS)-related services through the cloud assisted vehicular network. Before the full deployment of the 5G cellular network in the year 2020 [14], security and privacy related issues should be carefully addressed to boost its adoption [15; 16]. Furthermore, the ITS services based on the innovative 5G cellular network will require strong security because the data packets are relayed in the safety-critical vehicular environment [17]. That is, the design of secure protocols for the 5G-enabled ITS-related services is required. To send the videos recorded by the vehicle's cameras into the cloud server, we propose a secure and lightweight cloud-assisted video reporting protocol for 5G-enabled vehicular networks. Recently, [PERSON] et al. [18] and [PERSON] [19] have proposed the secure cloud-assisted video reporting protocols in the 5G-enabled networks. By including handover and certificate revocation algorithms, [PERSON] enhanced the Eiza-Ni-Shi protocol that was designed by using public key certificates. In this paper, we focus on resolving the following drawbacks of the Eiza-Ni-Shi protocol:  
* The Eiza-Ni-Shi protocol relies on convectional public key certificates that should be renewed in the vehicle periodically, e.g., every year. However, such periodic renewal is proved to be burdensome over the vehicular networks [20; 21; 22]. * The Eiza-Ni-Shi protocol is built on expensive pairing operations. Thus, the overall efficiency of the Eiza-Ni-Shi protocol can be decreased despite the merits of 5G cellular networks. * The Eiza-Ni-Shi protocol is designed by using an attribute-based encryption. When attribute-based encryption is used to achieve access control, the video sender should know the public key of the receiver. This preliminary makes the Eiza-Ni-Shi protocol to be only applicable in limited services. Also, we note that the cloud-assisted video reporting protocol should be designed to fulfill security requirements such as privacy, authorization and fine-grained access control over the vehicles. For example, the sender's personal data should not be revealed to unauthorized entities or even the reporting vehicles should not be traced by any malicious users.