Secure Transmission with Different Security Requirements Based on Covert Communication and Information-Theoretic Security in Presence of Friendly Jammer

In this paper, we investigate joint information-theoretic security andcovert communication on a network in the presence of a single transmit-ter (Alice), a friendly jammer, a single untrusted user, two legitimateusers, and a single warden (Willie). In the considered network, one of theauthorized users, Bob, needs a secure communication, and therefore hismessage must be sent securely, and at the same time, the other autho-rized user, Carol, needs covert communication, i.e., the existence of hiscommunication with the transmitter should not be detected by the war-den, Willie. In the proposed network model, it is assumed that for covertcommunication requirements, Alice will use an on-off strategy to sendthe data to the legitimate receivers of the network, so that it decides onthe sending of data at any specific time slot. One of the main challengesin covert communication is low data rate because we have to reduce thetransmission power such that the main message gets to hide in back-ground noise. In the proposed network, a jammer is employed to destroy the eavesdropper and warden’s channel. To eliminate the interferencecreated by the jammer, it has been proposed that the used jammer in thenetwork be friendly. In this study, in addition to using joint security ofinformation theory and covert communication, we examine the averagetransmission rate according to the limitations and requirements of covertcommunication and the requested quality of service by users, by creatingartificial noise in the network which is generated by a friendly jammer.