Covert Communication When Action-Dependent States is Available Non-Causally at the Transmitter

This paper studies covert communication over channels with action-dependent states when the state is available non-causally at the encoder. Covert communication refers to reliable communication between a transmitter and a receiver while ensuring low probability of detection at an adversary, which we refer to as "warden". It is well known that in a point to point Discrete Memoryless Channel (DMC), it is possible to communicate on the order of $\sqrt N $ bits reliably and covertly over N channel uses while the transmitter and the receiver are required to share a secret key on the order of $\sqrt N $ bits. This paper studies achieving positive covert and reliable communication rate, which is communication on the order of N bits over N channel uses, while the transmitter and the receiver share a secret key of negligible rate. We derive an achievable rate region by using block-Markov encoding and secret key generation from the Action-Dependent State Information (ADSI), which subsumes the best achievable rate region for channels with random states.