Physical layer security for cooperative relaying in broadcast networks

In this paper, we study the physical layer security for cooperative relaying in broadcast networks. We analyze two cooperative strategies, the decode-and-forward scheme and the compress-and-forward scheme. We can use decode-and-forward scheme only if the nodes which have both good communication channels from the source and high security clearance are chosen to serve as relays; otherwise, we cannot achieve physical layer security. While the compress-and-forward scheme is used, we can achieve physical layer security even though the relays have lower levels of security clearance than the destinations. We provide an achievable rate-equivocation region for this case.