Cognitive Interference Channels With Confidential Messages Under Randomness Constraint

The cognitive interference channel with confidential messages (CICC) proposed by Liang
et al.
is investigated. When the security is considered in coding systems, it is well-known that the sender needs to use a stochastic encoding to avoid the information about the transmitted confidential message to be leaked to an eavesdropper. For the CICC, the tradeoff between the rate of the random number to realize the stochastic encoding and the communication rates is investigated, and the optimal tradeoff is completely characterized.