A gateway apparatus supports differentiated secure communications among heterogeneous electronic devices. A communication port communicates via communication networks of different types with two or more associated devices having diverse secure communication capabilities. The gateway logic selectively authenticates the associated devices for group membership into a Secure Communication Group (SCG), and selectively communicates Secure Communication Group Keys (SCGKs) to the devices having the diverse secure communication capabilities for selectively generating session keys locally by the associated devices for mutual secure communication in accordance with the group membership of the associated devices in the SCG.