Covert Communication Gains From Adversary’s Uncertainty of Phase Angles

Optimization of Intelligent-Reflecting-Surface-Enabled Covert Communication in Multi-Sensor Systems

“…In [40,41], the spectrum and time resources have been adopted to improve the performance of covert communication. Moreover, in [8], the authors have proved that phase resources can also be utilized to enhance the performance of covert communication. They extended IRS covert communication to the complex Gaussian channel and introduced a novel codebook, i.e., the N-BPSK codebook.…”

“…This codebook is derived from the traditional BPSK codebook, and a simple reflect operation allows obtaining the full phase gain. This gain is crucial as traditional IRS covert communication requires biased reflection operations for each symbol, imposing high hardware demands and increased complexity on the IRS [8].…”

“…. , c n with a blocklength of n. In this work, we adopt the 2-BPSK codebook, proposed in [8], instead of the conventional Gaussian codebook or BPSK codebook. To construct the 2-BPSK codebook, we need to construct a BPSK codebook first.…”

“…Traditional encryption methodologies and techniques in physical layer security primarily concentrate on protecting the communication content [6,7]. Nevertheless, the mere protection of communication content no longer suffices to meet contemporary information security requisites [8,9]. To hide the communication behaviors, covert communication, also known as low probability of detection (LPD) communication, was proposed [10].…”

“…Alice utilizes IRS-reflected signals to covertly access one of the sensors, while Willie, as the detecting entity, aims to ascertain the presence of covert access. To reduce operational complexity and communication costs, Alice employs the 2-BPSK codebook proposed in [8] for covert communication. The main contributions of this paper are summarized as follows:…”