Abstract: Apparatus and a method are described for providing for multiple secure functions in a host or wireless radiotelephone. Access to the functionality of the radiotelephone is provided by means of a smart card or security token features contained therein. The determination of the secure function which is accessed is determined by encrypted credential information carried in the smart card. The smart card may be used for numerous applications, but is particularly useful in conjunction with radiotelephone devices having a plurality of secure communication levels. The radiotelephone device will activate the secure levels based on the security level algorithm carried in the smart card.

Abstract: A device driver (104) is used to provide a fail-safe interface between a plurality of client applications and a cryptographic card. Device driver (104) ensures separation between red data, black data, and command data. Device driver (104) uses objects and object handles to control data flow. Device driver (104) uses several simplex channels to control data flow. Each channel is managed separately using its own object, and each channel has unique access protection through the object handles. Within device driver (104), the simplex channel interfaces are kept separate and functional separation of the data and command memory is maintained to provide fail-safe data isolation.