Conditional Access System (CAS)
CAS stands for Conditional Access System. Conditional access (CA) is a technology used to control access to digital television (DTV) services to authorized users by encrypting the transmitted programming. CA has been used for years for pay-TV services.
There are numerous ATSC and DVB-compliant CA systems available for a broadcaster to choose from. The CA system provider provides the equipment and software to the broadcaster who then integrates the CA system into his equipment. CA is not designed solely for DTV. It can be used for digital radio broadcasts, digital data broadcasts, and non-broadcast information and interactive services. A CA system consists of several basic features:
- Basic attributes of subscription channels (PPC/PPV/Free/Floating View/Teasing).
- STB control (Recording/Search/Channel control; Lock/unlock/Reset/Restart STB).
- Notified STB upgrades.
- Regional restrictions.
- Adult content restrictions.
- Pin code restrictions.
- CAS Mail / FLASH Messages (General / Group / Unique).
- SC-STB pairing by terminal / head-end.
- Audience ratings and electronic wallet.
- Master-slave card.