Secure terahertz (THz) and millimeter-wave (mmWave) wireless communications. Enhanced security mechanisms for massive-MIMO, NOMA, and RSMA. Reconfigurable intelligent surface-empowered physical layer security approaches. Efficient security mechanisms for integrated terrestrial and non-terrestrial networks. Efficient security schemes for satellite communications. Technological advancements for secure aerial networks. Blockchain-empowered security schemes in 6G networks.

Secure optical wireless communications (OWC). Secrecy analysis and enhancement in security for 6G networks. Practical testbeds, experimental results, demonstrators. Potential threats and attacks in 6G networks. Topics of interest include, but are not limited to: - Advancements in physical layer security. The papers will be peer reviewed by at least three independent experts and will be selected on the basis of their quality and relevance to the theme of this special issue. More specifically, this special issue will bring together leading researchers and developers from both industry and academia to present their views on the current trends and challenges, addressing various concerns related to security and privacy in future wireless networks. In order to ensure that security concerns are adequately tackled and the necessary level of users privacy is maintained in 6G networks, the scope of this special issue will focus on the development of efficient and novel security designs and enabling techniques to address the underlying fundamental and practical challenges. This calls for a compelling need to revisit conventional security approaches and to design advanced energy-efficient, lightweight, secure, and low-cost security solutions, that perfectly fit in the context of 6G technologies. In specific, the majority of the current approaches consume a considerable amount of network resources, including energy, spectrum, time, etc., yielding a conflict with the severe requirements mentioned above. It should be highlighted that, although there are a considerable number of highly efficient security schemes, their applicability to 6G networks is still debatable. Accordingly, the development of effective security mechanisms should be an integral component of the 6G architecture. As the aforementioned technologies and services mature, privacy and security remain a predominant concern due to the centralized and decentralized data exchange, storage, and process, needed for the successful operation of 6G networks. The ultimate goal of these technologies is to realize self-sustaining, self-optimized networks with personalized user experience, in order to cater for the requirements imposed by the distinct nature of heterogeneous devices in the highly dynamic topologies identified for 6G networks.

Therefore, the evolution of 6G networks will be accompanied by diverse novel technological trends, including artificial intelligence (AI), data mining, cloud and edge computing, wireless mobile caching, network slicing, network function virtualization, as well as centralized and decentralized deep learning. The realization of such applications introduces a new level of stringent requirements necessary to support highly reliable and latency-sensitive communications between a massive number of data hungry Internet-of-Things devices. The speculative vision of future sixth-generation (6G) wireless networks is tailored for provisioning secure massive-scale connectivity, and thus, enabling diverse applications, including virtual/augmented/mixed reality services, haptics, flying vehicles, brain-machine interface, and telepresence, to name a few.

Mimo wireless