This paper reviews the information theoretic characterization of security in broadcast channels, in which a transmitter has both public and confidential messages intended for multiple receivers. All messages must be successfully received by their intended receivers, and the confidential messages must be kept as secret as possible from non-intended recipients. Various scenarios are considered in the context of two-user broadcast channels, for which known results on the secrecy capacity region are reviewed and corresponding coding schemes for achieving rates in these regions are described.Security issues arise naturally in broadcast channels due to the open nature of such communication. Each receiver is able to receive signals that contain all information flows from the transmitter, although sometimes with weak signal strength. Hence, some receivers may decode information flows that are not intended for them. However, confidential information flows should be kept as secret as possible from non-intended receivers. This requires that the transmitter employ techniques to guarantee such security constraints. Information theoretic approaches have been developed to achieve secure communication, initially over broadcast channels in References [1,2] and later on over other communication channels