The connected environment is enlarging rapidly due to the sensor-enabled growing smartness in devices or things around us in our daily life. The growing connectivity via computing and communication-enabled smart devices is also increasing the number of heterogeneous wireless technologies around us, resulting in greater security challenges. The traditional cryptography-centric security techniques are becoming nearly impractical for these very small and smart sensor-enabled devices due to the high volume of computation requirements. In today’s growing connected world scenario, physical layer security (PLS) is one of the potential solutions for sensor-enabled heterogeneous networks. The physical layer security focuses on signal level computation, identification, diversion, integration, and data analytics for secure localized-centric communication. The signal level operating techniques (e.g., beamforming, simultaneous wireless information and power transfer (SWIPT), multiple-input, and multiple-output (MIMO), etc.) have become high potential research areas in today’s dense and heterogeneous wireless networks. The density of IoT devices is also highly dynamic over space and time. Especially considering the growing smart environment around us, with different urgency requirements for information exchange.

These devices can bring interference concerns within the shared spectrum, highlighting a greater need for securing all aspects of networks. There is a growing interest in securing the availability and/or reliability of information exchange in IoT networks through new technologies (e.g., blockchain or cloud services). Nevertheless, wireless communication security can be implemented across several layers of the system. Traditionally, physical layer security employs the inherent characteristics of the propagation channels, such as interference, fading, and noise to realize keyless secure transmission through signal design and signal processing approaches. The benefits of employing PLS include less computational complexity compared to computation-based cryptography techniques. It also reduces challenges in the distribution and management of secret keys, especially in decentralized systems, such as IoT networks or fifth-generation (5G) and beyond heterogeneous networks. Furthermore, PLS techniques can be integrated through signal design and resource allocation depending on the prevailing conditions of the channel.

The aim of this Special Issue is to bring together original research and review articles about the physical layer security for sensor-enabled heterogeneous networks.

Potential topics include but are not limited to the following:

• Physical level security framework for sensor-enabled heterogeneous networks
• Sensing and sensor data aspects while designing physical layer security for IoT networks
• Optimizing secrecy capacity in sensor-enabled heterogeneous networks
• Location centric security framework for enabling smart services in heterogeneous networks
• Light-weight security architectures for next-generation heterogeneous networks
• Location verification in mobility centric heterogeneous network environments
• Beamforming centric security models for ultradense heterogeneous network environments
• Multiple input multiple-output (MIMO) based security models for heterogeneous networks
• Simultaneous wireless information and power (SWIPT) enabled network security models
• Edge computing-enabled security architecture for mobility centric heterogeneous networks
• Interference aware security models for highly dense heterogeneous networks