{'fraction_non_alphanumeric': 0.013683010262257697, 'fraction_numerical': 0.0, 'mean_word_length': 5.601503759398496, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 3, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Using ARM TrustZone to Implement Downloadable CAS Framework and Secure Media Pipeline in IPTV Client Devices

In IPTV industry, the major problem faced by device manufacturers that requires to be addressed is the number of proprietary, incompatible conditional access (CA) systems that different service providers have deployed. This paper presents design and implementation of Downloadable Conditional Access System (DCAS) framework and secure media pipeline using ARM TrustZone technology that enables different CA systems in a single client device. The CA system software is dynamically downloaded in the device via network and securely executed in the Trusted Execution Environment (TEE) provided by ARM TrustZone technology. This solution is as secured as any smartcard based CA system as the ARM TrustZone technology provides same level of hardware and software security.