One-Sided Secrecy Over The Two-Way Wiretap Channel

This paper studies the one-sided secrecy of a full duplex two-way wiretap channel. It is motivated by a practical communication scenario, where two legitimate users communicate with each other in the presence of an external eavesdropper and only one of the users wishes to keep its message confidential from the external eavesdropper for the sake of privacy. As a general result, we establish an achievable rate region via cooperative jamming and random binning mechanisms. An outer bound of the one-sided secrecy rate region is also derived for the two-way wiretap channel with one-sided secrecy. Besides, numerical results are provided for binary-input deterministic channels. In particular, the one-sided secrecy capacity region for the binary XOR channel is fully characterized. In general, channel prefixing demonstrates its advantage in enlarging the achievable one-sided secrecy rate region.