This paper investigates the fundamental performance limits of the two-user interference channel in the presence of an external eavesdropper. In this setting, we construct a n inner bound, to the secrecy capacity region, based on the idea of cooperative binning and channel prefixing in whic h the two users cooperatively design their binning codebooks and jointly optimize their channel prefixing distributions. Our achiev ability scheme also utilizes messagesplitting in order to allow for partial decoding of the inter ference 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 our proposed approach. Overall, our results provide structural insights on how the interference can be exploited to increase the secrecy capacity of wireless networks.
['Onur Ozan Koyluoglu', 'Hesham El Gamal']
Cooperative Binning and Channel Prefixing for Secrecy in Interference Channels