New outer bounds for wiretap channel with action-dependent states

摘要

The action-dependent states (ADSs) in wiretap channel is revisited. The transmitter aims to convey a confidential message to the receiver and protect it from the wiretapper as possible as he can. Actions are taken by the transmitter to influence the channel state information. For such a channel, Dai et al. first got an outer bound on the capacity-equivocation region which contains all the achievable transmission rates. We find a new outer bound and prove it is better than Dai's in terms of approximating the maximum rate at which the confidential message can be transmitted in perfect secrecy. Furthermore, the new outer bound provides the engineer with a more precise target to achieve higher transmission rates in the capacity-equivocation region.