Evolution of CAS Technology and MediaCAS
Taein Eom
Team Lead/Media Security Client Team., Altimedia Corp.
CAS(Conditional Access System) is one of the most important technologies for content providers.
CAS protects content provider’s profits by preventing unauthorized copying and distribution. It also helps to provide users with a better viewing experience by effectively utilizing video content in the operator’s service. To end this, CAS solution providers have developed their own products by combining various technologies and know-how for each provider on a hardware security environment such as OTP (One Time Programmable) and TEE (Trusted Execution Environment).
Due to this background, CAS technology was not standardized, and security methods and standards were bound to be different for each CAS provider. As a result, it was inevitable that significant effort would be incurred to implement CAS to the receiver (usually a set-top box). In this situation, Google, which has established itself as a strong player in the media service platform market, announced a specification called MediaCAS as early as 2016.
MediaCAS is designed to define the standard interface required for CAS service in the Android TV environment to enable CAS implementation more easily provided the HAL(Hardware Abstraction Layer) is pre-integrated by the SoC(System-on-chip). In addition, it enables the possibility of using multiple CAS providers simultaneously and selecting CAS service on a per-channel basis. Despite its many advantages, MediaCAS has not been widely adopted due to the impact on the influence and revenue of existing CAS providers. Moreover, the performance and secure robustness are also insufficient on initial releases.
However, the introduction of the Tuner Framework by Google for real-time broadcast signal processing in the Android environment significantly improved the problems in 2020. The adoption of Tuner Framework maintains strong security mechanisms, including Secure Media Path (SMP), and Trusted Execution Environment (TEE), while greatly reducing the effort required for MediaCAS implementation and service integration.
Altimedia has been supplying its in-house security solution, AltiProtect-CAS, to global IPTV, satellite, and cable operators based on its extensive experience and expertise. In South Korea, the interoperability and replacement among multiple CAS (based on DCAS, Downloadable-CAS) was a mandatory feature as a national standard. However, it has been relieved by the end of 2022, expanding the range of choices for various forms of CAS.
Altimedia has developed its own AltiProtect-CAS system fully complying with the latest MediaCAS specifications, allowing operators to maintain existing DCAS systems without modification. The CAS market is expected to continue to grow significantly in the future due to the increase in digital content and the emergence of cloud-based CAS and mobile CAS. And as Android TV becomes a mainstream platform, MediaCAS' market share will also increase considerably. Altimedia, which has the core technology for CAS and a greater understanding of Android and the set-top box environment, is also expected to play a more extensive role in the market.
