Covert Identification Over Binary-Input Discrete Memoryless Channels

This paper considers the covert identification problem in which a sender aims to reliably convey an (ID) message set of receivers via binary-input discrete memoryless channel (BDMC), and simultaneously guarantee that communication is with respect warden who monitors another independent BDMC. We prove square-root law for problem. states ID size exp(exp(Θ(√{ n})) can be transmitted over n uses. then characterize exact pre-constant Θ(·) notation. constant referred as capacity. show it equals recently developed capacity standard problem, somewhat surprisingly, achieved without any shared key between receivers. The achievability proof relies on random coding argument pulse-position modulation (PPM), coupled second stage performs code refinements. converse expurgation well results resolvability stringent input constraints.