A dynamic conditional access system based on cryptographic software for the IPTV set-top box

This paper proposes a dynamic conditional access system for the IPTV set-top box. The conditional access system dynamically downloads and executes cryptographic software for obtaining control words used for descrambling. The proposed system enables the IPTV set-top box to provide seamless conditional access services to IPTV subscribers without rebooting the set-top box or replacing a hardware security device while the running cryptographic software is changing. Therefore, the IPTV set-top box applying the proposed system also can provide channels that adopt different conditional access softwares.