Channel (broadcasting)

Operating system

Cloud computing security

Mathematics

Wireless

Computer science

Rayleigh fading

Cloud computing

Channel state information

Transmitter

Block (permutation group theory)

Philosophy

Fading distribution

Covert channel

Transmission (telecommunications)

Telecommunications

Security information and event management

Linguistics

Fading

Geometry

Additive white Gaussian noise

Covert

Computer network

IEEE Transactions on Information Forensics and Security

Covert communications enable a transmitter to send information reliably in the presence of an adversary, who looks to detect whether the transmission took place or not. We consider covert communications over quasi-static block fading channels, where users suffer from channel uncertainty. We investigate the adversary Willie's optimal detection performance in two extreme cases, i.e., the case of perfect channel state information (CSI) and the case of channel distribution information (CDI) only. It is shown that in the large detection error regime, Willie's detection performances of these two cases are essentially indistinguishable, which implies that the quality of CSI does not help Willie in improving his detection performance. This result enables us to study the covert transmission design without the need to factor in the exact amount of channel uncertainty at Willie. We then obtain the optimal and suboptimal closed-form solution to the covert transmission design. Our result reveals fundamental difference in ...

Covert Wireless Communications Under Quasi-Static Fading With Channel Uncertainty