An investigation of the possibility of defining a new conditional access application programming interface for digital television receivers

Abstract: Digital television broadcasters use conditional access (CA) systems to protect some of their services from being viewed by people not subscribing for these services. A manufacturer of digital television receivers develops applications to handle the CA systems that the receiver shall support. A problem for the application developer is that a CA application developed for one specific CA system is usually not reusable for other CA systems because of the differences between CA systems. The CA systems are different in both their application programming interfaces (API) as well as the types of functionality that they support. This master thesis presents a study of three APIs from different CA systems. The possibilities of defining a new CA API that supports all the functionality that is provided by existing CA APIs while still being as similar as possible to these existing APIs are investigated. The conclusion from the study is that it is not possible to define this new CA API because the studied CA systems are so different and only small parts of the provided functionality are shared between them.