Secret communication on the Z-Channel with cooperative receivers

Abstract

The discrete memoryless Z-Channel with a confidential message and a cooperative receiver (DM-ZC-CMCR) is considered. A noiseless one-sided rate-limited cooperation link exists between the two receivers. The secrecy level is measured by the equivocation rate. An outer bound on the secrecy-capacity-region DM-ZC-CMCR is derived. An achievable secrecy-rate region is proposed. The secrecy-sum capacity of a class of physically degraded DM-ZC-CMCR is characterized. An outer bound on the secrecy-capacity region for the physically degraded-Gaussian-ZC-CMCR (PD-Gaussian-ZC-CMCR) is derived. The secrecy-sum capacity for a class of physically degraded Gaussian-ZC-CMCR is characterized.