Covert Wireless Communication in IoT Network: From AWGN Channel to THz Band

 We demonstrated that covert communication is still possible in this occasion by utilizing the reflection or diffuse scattering from a rough surface. From the physical-layer security perspective, covert communication can enhance the security of IoT network from the bottom layer. Covert communication can prevent an adversary from knowing that a transmission has occurred between two users. In this paper, we consider covert wireless communications in an IoT network with dense deployment, where an IoT device experiences not only the background noise, but also the aggregate interference from other Tx devices.

 Our results show that, in a dense IoT network with lower frequency AWGN channels, when the distance between Alice and the adversary Willie , Alice can reliably and covertly transmit O(log2 √ n) bits to Bob in n channel uses. In an IoT network with THz (Terahertz) Band, covert communication is more difficult because Willie can simply place a receiver in the narrow beam between Alice and Bob in order to detect or block their LOS communications. We demonstrated that covert communication is still possible in this occasion by utilizing the reflection or diffuse scattering from a rough surface. From the physical-layer security perspective, covert communication can enhance the security of IoT network from the bottom layer.

keywords: Internet of Things; Physical-layer Security; Covert Communication; AWGN Channel; THz Band