Information Rates for the Relay Channel with Confidentiality

The problem of the relay channel with confidentiality was first formulated by Oohama in 2001, at which time an inner bound for the capacity region was stated. However, a proof of this inner bound remained unavailable in the literature, a fact that has hindered the development of further results involving more complex cooperative diversity channels. In this paper, we prove the inner bound on the capacity of the relay channel with confidentiality by using typical sequence decoding. We also generalize it by introducing an auxiliary random variable, and prove a corollary lower bound on the secret capacity of the channel