Control access kernel functionality verification in Set-Top Boxes via popup detection

This paper proposes a novel approach and system for functional verification of the Set-Top Boxes (STB) related to Conditional Access Kernel (CAK) functionality. The proposed solution is built on already existing BBT testing system with supporting audio-video capturing device, in the form of two newly developed functional device drivers. Since the CAK functionality, within the STB with a smart card, can be monitored via pop-ups at the output, the idea of the proposed methodology is to detect pop-up in the output video signal and conclude from it about STB functionality. For this purpose a novel algorithm for pop-up detection has been developed. Specifically, given the specially designed input test sequences and special STB state conditions, the pop-up window is invoked at particular time instance. The reference a priory known appearance of the pop-up window in the output of STB is compared to the detected pop-up from the STB output. Based on this comparison, in specific time intervals, a decision is made about the STB functionality in terms of CAK functionality. The experimental results of the proposed system performance have shown that the testing system is accurate and robust, provided a rough pop-up window model is given in advance or manually developed.