A media processing device, such as a set top box, having selectable hardware and software components for forming media pathways compliant with security definitions provided by downloaded or preinstalled software applications. Such applications may include, for example, a downloadable conditional access security or DRM element/definition. A corresponding certification process can entail certifying a portion of an overall secure pathway, with one or more applications providing the final portion of the certification. Alternatively, predefined conditional access mechanisms are provided, with an application establishing which mechanism is to be used. In various embodiments, a set top box or resident software application may exchange capabilities with other devices in a media consumption network to compare against the requirements of the software application. Once the information exchange is complete, the software application may select which one or more modes of operation or media pathways, if any, that it will permit.