We study the covert communication over K-user-pair discrete memoryless interference channels (DM-ICs) with a warden. It is assumed that the warden's channel output distribution induced by K “off” input symbols, which are sent when no communication occurs, is not a convex combination of those induced by any other combination of input symbols (otherwise, the square-root law does not hold). We derive the exact covert capacity region and show that a simple point-to-point based scheme with treating interference as noise is optimal. In addition, we analyze the secret key length required for the reliable and covert communication with the desired rates, and present a channel condition where a secret key between each user pair is unnecessary. The results are extended to the Gaussian case and the case with multiple wardens.

In this paper, the covert communication scenario over K-user-pair discrete memoryless interference channels with a warden is studied. We assume that the wardens channel output distribution induced by K "off input symbols, which are sent when no communication occurs, is not a convex combination of those induced by any other combination of input symbols (otherwise, the square-root law does not hold). We derive the exact covert capacity region and show that a simple point-topoint based scheme with treating interference as noise is optimal. In addition, we analyze the secret key length required for the reliable and covert communication with the desired rates, and present a channel condition where the secret key between each user pair is unnecessary.

We consider the problem of covert communication over wireless adhoc networks in which (roughly) n legitimate nodes (LNs) and nκfor κ > 0 non-communicating warden nodes (WNs) are randomly distributed in a square of unit area. Each legitimate source wants to communicate with its intended destination node while ensuring that every WN is unable to detect the presence of the communication. In this scenario, we study the throughput scaling law. Due to the covert communication constraint, the transmit powers are necessarily limited. Under this condition, we introduce a preservation region around each WN. This regionsuitably modified by taking a detour around each preservation region. To avoid the concentration of detours resulting extra relaying burdens, we distribute the detours evenly over a wide region. In the proposed HC scheme, we control the symbol power and the scheduling of distributed multiple-input multiple-output transmission. We also present upper bounds on the throughput scaling under the assumption that every active LN consumes the same average transmit power over the time period in which the WNs observe the channel outputs. For 0 <; κ <; 1, these upper bounds match with the achievable throughput scalings.

We study the throughput scaling law of covert communication over wireless adhoc networks where (roughly) n legitimate nodes (LNs) and nκfor 0 <; κ <; 1 warden nodes (WNs) are randomly distributed in a unit area. Each legitimate source wants to communicate with its destination while ensuring that each WN is unable to detect the presence of communication. A preservation region, where the transmission of the LNs is not permitted, is introduced around each WN to increase the transmit power of the LNs outside the preservation regions. For achievability, multi-hop (MH), hierarchical cooperation (HC), and hybrid HC-MH schemes in the literature are utilized with some modifications. In the MH and the hybrid schemes, because the preservation regions may block the direct data paths, a detouring method that distributes the detours evenly over a wide region is proposed to avoid the concentration of relaying burdens. In the HC scheme, we properly control the symbol power and the MIMO transmission scheduling. We also present matching upper bounds on the throughput scaling under an assumption that every active LN consumes a same average transmit power over the time period that the WNs observe.

In smart metering systems, a rechargeable battery can be utilized to protect the privacy of a user from the utility provider by partially masking the load profile of the user. In this line of research on using rechargeable batteries for privacy protection, most existing works have studied only single-user systems using rechargeable batteries. In this letter, we consider a multi-user scenario where the power supplies of two or more users are combined before sending them to the utility provider. We study the effect of such a user cooperation on enhancing the user privacy by deriving upper and lower bounds on the minimum leakage rate. Our simulation results show that the information leakage of each user can be reduced by a factor of the total number of cooperative users.