Sharif Digital Repository

This paper introduces a new applicable Gaussian wiretap channel with side information. In this channel, the state of the channel to the wiretapper is separated from the main channel's one. It means that the legitimate receiver and the wiretapper are listening to the transmitted signal through the different channels with different channel states which may have some correlation to each other. The state of the main channel, is assumed to be known at the transmitter, helps the sender to encrypt its messages. The achievable equivocation-rate region for this model is drived in the Gaussian case and the results are reduced to the previous works as special cases  

We study a relay channel with confidential messages (RCC), which involves a sender, a receiver and a relay. In the RCC, a common information must be transmitted to both a receiver and a relay and also a private information to the intended receiver, while keeping the relay as ignorant of it as possible. The level of ignorance of the relay rather than the private message is measured by the equivocation rate. We consider two error probability exponents (reliabilities) E1, E2 of exponentially decrease of error probability of the receiver decoder and the relay decoder, respectively. For E = (E1, E2), the E-capacity region is the set of all E-achievable rates of codes with given reliability E. We... 

The secrecy problem in the state-dependent cognitive interference channel is considered in this paper. In our model, there are a primary and a secondary (cognitive) transmitter–receiver pairs, in which the cognitive transmitter has the message of the primary one as side information. In addition, the channel is affected by two channel state sequences, which are known at the cognitive transmitter and the corresponding receiver, separately. The cognitive transmitter should cooperate with the primary one, and it wishes to keep its message secure at the primary receiver. The achievable equivocation-rate regions for this channel are derived using two approaches: the binning scheme coding and...