The standardization activities of the fifth generation communications are clearly over and deployment has commenced globally. To sustain the competitive edge of wireless networks, industrial and academia synergy have begun to conceptualize the next generation of wireless communication systems (namely, sixth generation, (6G)) aimed at laying the foundation for the stratification of the communication needs of the 2030s. In support of this vision, this study highlights the most promising lines of research from the recent literature in common directions for the 6G project. Its core contribution involves exploring the critical issues and key potential features of 6G communications, including: (i) vision and key features; (ii) challenges and potential solutions; and (iii) research activities. These controversial research topics were profoundly examined in relation to the motivation of their various sub-domains to achieve a precise, concrete, and concise conclusion. Thus, this article will contribute significantly to opening new horizons for future research directions.

The significance of the Internet of Drones (IoD) is increasing steadily and now IoD is being practiced in many military and civilian-based applications. IoD facilitates real-time data access to the users especially the surveillance data in smart cities using the current cellular networks. However, due to the openness of communication channel and battery operations, the drones and the sensitive data collected through drones are subject to many security threats. To cope the security challenges, recently, Srinivas et al. proposed a temporal credential based anonymous lightweight authentication scheme (TCALAS) for IoD networks. Contrary to the IoD monitoring framework proposed by Srinivas et al., their own scheme can work only when there is one and only one cluster/flying zone and is not scalable. Moreover, despite their claim of robustness, the investigation in this paper reveals that Srinivas et al.’s scheme cannot resist traceability and stolen verifier attacks. Using the lightweight symmetric key primitives and temporal credentials, an improved scheme (iTCALAS) is then proposed. The proposed scheme while maintaining the lightweightness provides security against many known attacks including traceability and stolen verifier. The proposed iTCALAS extends scalability and can work when there are several flying zone/clusters in the IoD environment. The formal security proof along with automated verification using ProVerif show robustness of proposed iTCALAS. Moreover, the security discussion and performance comparisons show that the iTCALAS provides the known security features and completes authentication in just 2.295 ms.

The continuous innovation and progression in hardware, software and communication technologies helped the expansion and accelerated growth in Internet of Things based drone networks (IoD), for the devices, applications and people to communicate and share data. IoD can enhance comfort in many applications including, daily life, commercial, and military/rescue operations in smart cities. However, this growth in infrastructure smartness is also subject to new security threats and the countermeasures require new customized solutions for IoD. Many schemes to secure IoD environments are proposed recently; however, some of those were proved as insecure and some degrades the efficiency. In this article, using elliptic curve cryptography, we proposed a new authentication scheme to secure the communication between a user and a drone flying in some specific flying zone. The security of the proposed scheme is solicited using formal Random oracle method along with a brief discussion on security aspects provided by proposed scheme. Finally, the comparisons with some related and latest schemes is illustrated.