Three-user cognitive multiple-access channels with confidential messages

The two-user discrete memoryless cognitive multiple-access channel with confidential messages (DM-CMAC-CM) has been studied in the literature with a result for the secrecy capacity region. In this paper, we study a more general and practical model (three-user DM-CMAC-CM), although similar generalizations have been intractable in some studied cases, and obtain a capacity-equivocation and secrecy capacity region results including previous results as its special cases.