Date Added: May 2009
In this paper, the authors investigate the fundamental performance limits of the two-user interference channel in the presence of an external eavesdropper. In this setting, they construct an inner bound, to the secrecy capacity region, based on the idea of cooperative binning and channel prefixing in which the two users cooperatively design their binning codebooks and jointly optimize their channel prefixing distributions. Their achievability scheme also utilizes message-splitting in order to allow for partial decoding of the interference at the non-intended receiver. Outer bounds are then derived and used to establish the optimality of the proposed scheme in certain cases. In the Gaussian case, the previously proposed cooperative jamming and noise-forwarding techniques are shown to be special cases of their proposed approach.