Wireless sensors and multimedia communication devices are increasingly becoming a part of our everyday lives and societies, as a part of the growing Internet of Things. Subsequently, issues surrounding their safety and security are becoming ever more important. This is true, not only for overtly hostile environments such as for defence and national security, but also for covert commercial platforms handling private and sensitive information.

With the advent of new solid-state devices and spin-off investigations from the development of military systems, a host of new technologies have come to the fore, including sophisticated RF sensing, activating, signal processing, and communications. The ability to protect against hostile actions to sense, access, process, command, and control covert information is of utmost importance and is vital for the success of this next generation of communication systems and networks.

The aim of this special issue is to document the state of the art in the security of covert communication networks, especially in hostile environments. This includes the identification of current challenges for the field, the development of novel technologies and strategies, and discussion and exploration of future solutions. Both research and focused review articles will be considered.

Potential topics include but are not limited to the following:

• Advanced devices and systems for covert communication systems
• Maintaining secure communications in hostile environments
• Intrusion detection in covert communication networks
• Countermeasures against communication network intrusion
• System performance modelling and simulation in hostile environments
• Maintaining reliability and survivability for susceptible networks
• Emerging surveillance techniques using active and passive sensing
• Advanced networked and agile systems for hostile environments
• Wireless sensors and multimedia, cooperation-based systems, and cognitive radio networks operating in hostile environments
• Distributed and coherent signal processing for physical security communications
• Emerging manned and unmanned covert applications for air, sea, land, and space