Common Interface

Common Interface [ kɒmən ɪntəfeɪs ] ( German Common Interface), CI, is an interface of DVB receivers, which is compatible with the to be found in notebooks PCMCIA slot. Meanwhile, there are many receivers and TV sets a CI slot. Cards that fit into this slot, hot CI modules.

Common Interface for decrypting pay TV

The most important and most common group of CI modules form the Conditional Access Modules ( CAMs), which in turn can accommodate a Smartcard and / or have installed a chip. These are used for decryption of received DVB data (usually pay television or radio). The CI module is the interface between the encrypted data and the smart card on which is the key. There are several systems (eg Nagravision conditional access system or general ), each of which supports at least one CAM.

Other areas of application

Another field of application of the Common Interface modules are designed to enable an interpretation of additional video codecs. In the past, set in digital video transmission is usually on the MPEG -2 format, which meant that many - particularly the elderly - Powerful receiver exclusively govern the interpretation of the MPEG -2 format. Many broadcasters place but now on the MPEG -4 format, as this is less data consuming and at the same data rate 1.5 times the number may be transmitted to radio stations while maintaining quality. CI - specific modules are able to convert the MPEG-4 data and to return as a MPEG-2 data to the receiver. Here, the CI module deceives the receiver so that it is in the not directly interpretable for the terminal data to an encrypted transmitter and the CI module can decrypt it.

In some devices, the common interface is used by service technicians to evaluate malfunctions and faults can.

Further areas of applicability of the Common Interface modules were to interpret Multimedia Home Platform Applications (MHP ) and special network cards, which should allow connected computers to download data plan on DVB- multiplexing applications. This application areas have not been successful on the market. The public broadcasters have suspended MHP services.

CI ( CI Plus)

In CI is a proprietary development of the DVB -CI standards, which was specified by the CAM manufacturers Neotion and SmarDTV and the four televisions manufacturers Panasonic, Philips, Samsung and Sony. Since CI standard not adopted the DVB consortium represents is no direct successor of DVB- CI system. The DVB Consortium, made up of more than 270 stations, equipment manufacturers, providers and other industry representatives, for several years working on version 2.0 of the DVB -CI standards. Version 1.4 of the CI specification, however, to be published again by the DVB consortium.

Changes compared to the CI - 1.0 standard

CI allows broadcasters send along additionally use information in the television signal, so-called Usage Rules information (URI). These instructions allow content providers to limit the use of its by CI protected contents on CI certified terminals; they determine whether and how the relevant content may be used. They can for each individual shipment

• The recording to a maximum of 90min limit (usually as " time-shift -only" implemented),
• Playback of TV recordings time limit (but contains the current CI Specification Version 1.3 also unlimited access right )
• TV recordings using a device key to the respective recording device bind (recordings CI protected content can not be played back on other devices ),
• Determine whether and in what resolution (possibly downscaling on SDTV) is to be the video output from the analog output (eg SCART) and whether this is copy protection (Macrovision ) is provided, such as for HDTV broadcasts.

The CI technology includes other changes compared to the current CI 1.0 standard:

• CI encrypted previously decrypted contents again so that they can not be picked up at other interfaces.
• Means activated " host service Shunning ", modules, which are based on the old DVB- CI 1.0 standard can be excluded from the decryption CI protected services (which Shunning is not set to active, the respective service can be used both by a suitable DVB-CI module be decrypted or a suitable CI module).
• It will no longer be able to decrypt more than one pay-TV service, provided to apply these different encryptions ( twin or multi -CAM), such as Arena Sky or ORF SF SkyAT. This gives users an even tighter bound to a broadcaster ( the user can, however, use different CI modules in parallel when its receiver over a corresponding number of CI slots available ).
• The output of HD signals is only HD Ready Certified devices be possible, since only these to-end encryption of the data stream support to the display via HDCP.
• This from the " CI Consortium " (CI Plus LLP ) commissioned TrustCenter CI compatible devices at the user remotely out of operation ( Revocation, for example, if it is determined that a device compromised the copy protection).

These restrictions relate mainly DVB- recorder. Receiver without a recording function are affected by many of these restrictions only partially.

Technical action of " host Shunning Flags"

CI uses the same hardware interface (PCMCIA) as the original Common Interface.

Existing receivers that do not have a CI slot will work with CAMs of the CI - 1.0 standard without problem: Due to the backward compatibility with CI 1.0, the above-mentioned host Shunning flags ( "Instructions" ) are completely separated from the video stream and encryption. That is, the Broadcast streams and their encryption are not changed. CI slots and CA Modules ( CAMs) after CI 1.0 standard therefore will just ignore the host Shunning flags. If a CI CAM inserted into a CI -1.0- Schacht, the decryption CI protected content usually does not work.

So consumers can use their past CI 1.0 devices can continue to use ( new subscribers have to follow some precautions depending on the broadcaster, such as the serial number of a certified receiver with a CAM -enabled smart card can show and in the case of some cable broadcasters appropriate to the CAM firmware eighth ), provided for the available stations, there is a CAM of 1.0 standard.

Receiver with a CI slot, however, the decryption will stop when a previous CAM of 1.0 standard is plugged in (assuming the respective transmitter has "Host Service Shunning " is enabled, otherwise also work old modules of the DVB -CI -1.0 standards ).

Criticism of CI

The specification developed is strongly criticized by consumer advocates, because the content providers through him received a lot of power over the new receiver. Often the CI specification is condemned as patronizing and restricting the viewer rights. The Consumer NRW recommends potential buyers currently buy any HD satellite receiver, in order to avoid a bad investment due to the fast-paced market. The Consumer Rhineland- Palatinate warns due to the spectator unfriendly properties of the CI technology before a technical incapacitation and considerable tutelage of television viewers.

The criticisms in detail are:

• The user can popular features such as fast-forwarding during commercials or dubbing recordings on a removable disk will be denied. When the function is disabled decides the content provider.
• Customers are more closely tied to a pay- TV provider, as it is not possible to apply different encryptions ( twin or multi-cam ). Thus, a customer can receive alternately Arena and Sky or ORF, SF and SkyAT for example, he would have to change every time the CAM (or he buys a receiving device, which has several CI slots, and can therefore also operate several modules in parallel ).
• The use of DVB receivers is compared to the current CI 1.0 standard significantly restricted (see above)
• Whether the huge installed base of equipment by the best- DVB- CI slot can be changed over to CI Plus is unclear.
• Because of the high hardware requirements and license costs a CI CAM costs more, in addition, a new CI capable receiver is necessary if a manufacturer does not offer a firmware upgrade for the existing device. A recording of HD channels is not possible with retrofitted in this way receivers.
• Multi-tuner solutions that allow parallel reception of more than one shipment ( eg, recording and television at the same time, picture-in- picture), are no longer usable, since there is not a program can be decrypted at the same time as. To devices used with multiple CI slots and a corresponding plurality of CI modules, you can work around this limitation. In addition to CI version 1.4 " dual- tuner support" feed hold in the specification.
• Multiroom solutions in which ( a) is a central receiver in the house the decoded television signal or (b) a "TV Server" TV recordings over a network, for example, multiple receivers in the house available are not possible,
• It is questionable whether PC-based TV recorder (eg Linux-based receiver and HTPC) a CI - licensing can be obtained so that this product category could disappear from the market on success of CI. Reason: with the re - encryption (see above) should be prevented that the TV content can be picked up, for example to USB, Ethernet, disk interfaces.
• Customers must accept that their receiver or recorder can be excluded by the trust center via signal transmission from the CI decryption when the CI security of the receiver is no longer guaranteed ( compromised ). Except for the CI functionality, the receiver but continues to operate smoothly. Only through a new firmware the manufacturer, probably would no longer be playable with the previous shots, affected receivers were used for the decryption CI protected contents again.

A critically on the customer side of HD and CI reportable, professionally -made video was deleted by the HD Plus GmbH on YouTube due to unspecified copyright infringement. The exact author of the video is not known, but after the deletion of the video copies of the video were from other YouTube users uploaded as a reaction again and it was released a counter displaying the video creator.

Sectoral interests

Interests of the rights holder

Since it is re-encrypted in DVB recorders with CI , the TV show only is still playable on this device, the rights holders are hoping a better copy, that is a much lower digital transmission over the Internet, black copies, etc. and thus lower sales.

Interests of the broadcasters and broadcasters

With a better copy protection and the possibility of television recordings to prevent, for example, new films once fully, the broadcasters and broadcasters to gain a better bargaining position when buying film and television rights.

Cable operators, such as cable Germany, Kabel BW, Cablecom, Unity Media and Tele Columbus, have already announced plans to support the specification accordingly.

According to SES Astra is the reception of the HDTV versions of RTL, VOX, ProSieben, kabel eins and Sat.1 available since autumn 2009 and January 2010 on the new Astra HD offer, requires a CI compatible receiver. According to Astra reception is possible from HD also on HD receiver with a conventional CI interface; the HD receivers have to be adapted for this purpose by a firmware update for HD (possibly existing comfort functions are thus disabled or limited ). The end of 2010 such updates for 100 devices from 19 manufacturers were available. Sky Germany (formerly Premiere ) announced in September 2010, also offer a CI Plus module until Christmas 2010. In December 2010, however, it turned out that this negotiated a temporary offer in conjunction with new equipment and fewer manufacturers.

Since customers can receive broadcasts with CI statements with devices that still have the "old" CI slot, unlimited, broadcasters or broadcaster can only enforce a comprehensive introduction of CI when

• Switch to a coding, for which there is no CAMs after the 1.0 standard. In the case of the HD offer from Astra HD exist rumors that such encryption is to be applied.
• Broadcaster with an existing customer base then not only would all smartcards, but all recognized in the past, devices with CIs after the 1.0 standard exchange.
• In addition, manufacturers of CAM modules would ( esp. from the gray market ) to run this action if they offer just such CAMs.
• Broadcaster with an existing customer base could provide new HDTV channels provided with a new encryption, so that they can implement for customers who need a new receiver for HDTV, CI enabled receiver.

Interests of the manufacturer

Manufacturers of televisions and set -top boxes, especially those with DVB-C receivers ( digital cable ), let their systems are not costly and functional limitations with providers such as Sky, Cable Germany, Unity Media, etc. license, such devices can so far only sell in smaller quantities. Reason: The providers refuse to conclude a pay-TV subscriptions if an end customer can not specify a serial number of a licensed device at the conclusion.

After most of the German cable network operators have their support of CI announced (see above), provides CI especially for television manufacturers the opportunity is to integrate devices with additional DVB- C receiver and CI support CAM modules to be able to settle. The founding members of CI Plus LLP were all television manufacturers who had little or no DVB -C - enabled end devices on offer in Germany.

In addition, larger manufacturers in CI the chance for higher market shares may know where she CI as an "innovation " market, so that consumers confuse ( fear of future incompatibility of their current devices) and thus to gain market share. The same is probably true for Kudelski / Nagravision / SmarDTV, the licensor of CI .

A number of other consumer electronics manufacturer supports the specification or already announced it, such as Sony, Philips, Topfield, Loewe, JVC, LG, Panasonic, Samsung.

Even manufacturers such as NDS ( VideoGuard encryption system ), Irdeto, Neotion, SmarDTV or Smit are now offering CI compatible Conditional Access modules, on the pay packages of some cable companies (DVB- C, DVB -C2 ), satellite providers (DVB- S2 HD ) and pay- TV channels such as Sky can be obtained.

Interests of consumers

CI is compared to the normal common interface, technical consumer only disadvantages, some of which are enumerated above. There is only a theoretical chance to indirectly benefit from an increased willingness of content providers to offer better content via this method.