Strong secrecy in compound broadcast channels with confidential messages

In this paper the compound broadcast channel with confidential messages is studied, where it is only known to the transmitter and receivers that the actual channel realization is fixed and from a pre-specified set of channels. An achievable rate region for the strong secrecy criterion is derived. Further, a multi-letter outer bound is given, which establishes, together with the achievable rate region, a multi-letter expression of the strong secrecy capacity region.