Effects of cooperation on the secrecy of multiple access channels with generalized feedback

We investigate the effects of user cooperation on the secrecy of multiple access channels with generalized feedback (MAC-GF). We show that cooperation can increase the achievable secrecy region. We propose achievable schemes which use compress-and-forward (CAF) based transmission strategies. CAF based strategies allow users to increase their rates up to levels which are not decodable by the cooperating partners, consequently improving the secrecy of the users. We also provide outer bounds on the achievable equivocation rates. The outer bounds we derive depend only on the channel inputs and outputs, and hence, are easily computable. Finally, we specialize our results to a Gaussian MAC-GF, and present numerical results which demonstrate the beneficial effects of cooperation on secrecy.