common interface (DVB) (CI)

The Common Interface(CI+) is the interface for set-top boxes and satellite receivers. This interface was specified by DigitalVideoBroadcasting( DVB) and is used to connect an access module.

The CI module is inserted into a slot in the set-top box or DVB reception device. It is similar to a PCMCIA card and contains all functions for descrambling, processing of Entitlement Management Messages( EMM), Entitlement Control Messages( ECM) and Conditional Access( CA).

A smart card is inserted intothe CI module, on which the access authorizations for the various TV programs are stored.

Common Interface module (CI), photo: areadvd.de

A CA module for decryptingpay TV can also be plugged into the common interface, as can modems, memory expanders and game consoles.

Since cable network operators and program providers offer proprietary CI interfaces, there is an initiative by the Consumer Electronics Association in the German Electrical and Electronic Manufacturers' Association ( ZVEI), the Gesellschaft für Unterhaltungs- und Kommunikationselektronik (gfu) and Kabel Deutschland GmbH to standardize the CI interface under the name CI-Plus (CI+). The CI-Plus standard supports copy protection and offers network operators the option of using their individual encryption technologies with their own decryption modules.