Coding for wiretap channels: Channel resolvability and semantic security

Wiretap channels form the most basic building block of physical-layer and information-theoretic security. Considerable research work has gone into the information-theoretic, cryptographic and coding aspects of wiretap channels in the last few years. The main goal of this tutorial article is to provide a self-contained presentation of two recent results - one is a new and simplified proof for secrecy capacity using channel resolvability, and the other is the connection between semantic security and information-theoretic strong secrecy.