The Common Interface or CI or CI module is an expansion slot for electronic modules that are available in modern TVs, including so-called “smart” TVs based on Android, receivers, computer boards, etc. The interface allows you to view closed and encoded channels. In simple terms, the slot is needed for satellite operators, cable television.
In fact, the interface consists of two parts.
The first is a CAM module. This is a plug-in adapter for connecting closed-channel decoding cards to the CI slot, which is usually bundled with the TV, or purchased separately. The CAM module looks like this (bottom view):
The second part is a decoding card. This is an electronic smart card that is inserted into the CAM module. It stores the data of the subscriber, including the period of subscription, payment of channels, etc. You can get it from the operator to whom you plan to connect. The card looks like this (in the image it is inserted into the CAM module, and the CAM module itself is connected to the TV):
The standard version of CI decodes the television signal and transmits it for further processing in unencrypted form to the TV. This means that the signal can be recorded or copied. The new version of CI + works with reverse encryption. It is difficult to record a signal or copy in this case, you need to use special equipment. The content owner, in turn, can do what he wants with him. For example, prohibit viewing or prohibit rewinding of advertisements.