Physical Layer Security for a 3-Receiver Broadcast Channel

In this paper, we study the physical layer security for the 3-receiver broadcast channel, which is useful in describing the wireless broadcast scenario, where a private message is kept secret from one of the receivers. This model is more general than the previously studied broadcast channels with private messages, since conditions on the receivers are general, and the wiretapper receives the common message. Our main results are the inner and outer bounds to the rate equivocation region, which we derive using code partitioning in tandem with double-binning. We derive the outer bound when the receiver with the private message is more capable and less noisy than the wiretapper, respectively.