An Outer Bound to the Secrecy Capacity Region of CMAC with Confidential Messages and Non-Causal CSI

In this paper, we investigate the problem of secret communication over a Compound Multiple Access Channel (CMAC) with confidential messages and non-causal Channel State Information (CSI) at both the transmitter and the receivers. In this channel, one common message M-0 is sent to both of the receivers, the private messages M-1 and M-2 are sent to the corresponding receiver, while M-1 is only decoded by the first receiver and is kept confidential from the second receiver. We provide a theorem to give the outer bound to the secrecy capacity region of this channel model. The outer bound to the secrecy capacity region of this paper subsumes Csiszar and Korner's region of the broadcast channel with confidential messages and the region of CMAC with confidential messages and no side information as its special case. The proof of the theorem is presented in details.