Abstract: The invention is to be used in the Digital Video Broadcasting—Common Interface environment for accessing the Conditional Access Module (CAM). The host application handles objects of the Conditional Access (CA) through a private Application Program Interface (API). Each CAM may have its own private CA API but the data channel remains identical whatever the CAM is. This new mode coexists with the two already defined modes: low level Man Machine Interface, and high level Man Machine Interface. If a Set top Unit “understands” the private CA Application Program Interface (API), then it may access the features of the plugged CA through its private CA API Protocol. Otherwise, it remains on the standard API. With this extension, an STU can have a Conditional Access User Interface which perfectly fits into the overall User Interface of the STU. Thus b broadcaster can ensure that its look and feel are respected on its STUs.