Common Interface
Common Interface [ ˈkɒmən ˈɪntəfeɪs ] ( German general interface ), CI , is an interface for DVB receivers that is compatible with the PCMCIA slot found on notebooks . Many receivers and TV sets now have a CI slot. Cards that fit in this slot are called CI modules .
Common interface for decoding pay TV
The most important and most common group of CI modules are the Conditional Access Modules (CAMs), which in turn can accommodate a smart card and / or have a chip built in. These are used to decrypt received DVB data (usually pay TV or radio). The CI module is the interface between the encrypted data and the smart card on which the key is located. There are different systems (e.g. Nagravision or general conditional access system ), of which each CAM supports at least one.
Further areas of application
Another area of application of the common interface are modules that are intended to enable the interpretation of additional video codecs. In the past, the MPEG-2 format was generally used for digital video transmission , with the result that many - especially older - receiving receivers can only interpret the MPEG-2 format. However, many broadcasters are now relying on the MPEG-4 format, as this is less data-intensive and 1.5 times the number of broadcast stations can be transmitted with the same data rate with the same quality. Special CI modules are able to convert MPEG-4 data and return it to the receiver as MPEG-2 data. The CI module leads the receiver to believe that the data that cannot be directly interpreted by the end device is an encrypted sender and that the CI module can decrypt it.
With some devices, the common interface is used by service technicians to evaluate malfunctions and faults.
Other areas of application for the Common Interface were modules for interpreting multimedia home platform applications (MHP) and special network cards that were supposed to enable connected computers to download applications to DVB multiplexes via data services. However, these areas of application have not established themselves on the market. The public service broadcasters have stopped their MHP services.
CI + (CI Plus)
CI + is a proprietary further development of the DVB-CI standard, which was specified for the first time in 2007 by the CAM manufacturers Neotion and SmarDTV as well as the four television manufacturers Panasonic , Philips , Samsung and Sony . Since CI + is not a standard adopted by the DVB consortium, it is not a direct successor to the DVB-CI system. The DVB consortium, to which more than 270 broadcasters, device manufacturers, providers and other industry representatives belong, worked for several years on version 2.0 of the DVB-CI standard. This was finally published by the DVB consortium as BlueBook. The last revision took place in February 2019.
Changes compared to the CI 1.0 standard
CI + allows broadcasters to send usage information, so-called Usage Rules Information (URI), to the television signal. These instructions enable content providers to restrict the use of their CI + protected content on CI + certified devices; they determine whether and how the respective content may be used. You can do this for each individual shipment
- limit the recording to a maximum of 90 minutes (mostly implemented as "time shift only"),
- time limit the playback of television recordings (however, the current CI + specification (version 1.3) also includes unlimited access rights),
- Bind TV recordings to the respective recording device using a device key (recordings of CI + protected content cannot be played back on other devices),
- Define whether and in which resolution (possibly downscaling to SDTV ) the video output should take place via the analog output (e.g. SCART ) and whether this is provided with copy protection ( Macrovision ), such as with HDTV broadcasts.
The CI + technology includes further changes compared to the current CI 1.0 standard:
- CI + encrypts previously decrypted content again so that it cannot be accessed at other interfaces.
- By activating "Host Service Shunning", modules based on the old DVB-CI-1.0 standard can be excluded from the decryption of CI + protected services (if Shunning is not set, the respective service can be from a suitable DVB-CI Module or a suitable CI + module).
- It will no longer be possible to decrypt more than one Pay TV offer if they use different encryption methods (twin or multi-CAM), e.g. B. Arena + Sky or ORF + SF + SkyAT. This means that the end customer is even more closely bound to a broadcaster (the user can, however, use different CI + modules in parallel if his receiving device has a corresponding number of CI + slots).
- The output of HD signals will only be possible on HD ready -certified devices, since only these support end-to-end encryption of the data stream up to the display via HDCP .
- The trust center commissioned by the “CI + Consortium” (CI Plus LLP) can remotely disable CI + -compatible devices at the user's premises (revocation, e.g. if it is found that a device has compromised copy protection).
These restrictions mainly affect DVB recorders. Recipients without a recording function are only partially affected by many of the restrictions mentioned.
Technical mode of operation of "Host Shunning Flags"
CI + uses the same hardware interface ( PCMCIA ) as the original Common Interface.
Previous receivers that still have a CI slot will continue to work without any problems with CAMs of the CI 1.0 standard: Due to the downward compatibility with CI 1.0, the above-mentioned. Host shunning flags ("instructions") completely separate from the video stream and the encryption. This means that the broadcast streams and their encryption are not changed. CI slots and CA modules (CAMs) based on the CI 1.0 standard will therefore simply ignore the host shunning flags. If a CI + CAM is inserted into a CI-1.0 slot, the decryption of CI + -protected content usually does not work.
Consumers can therefore continue to use their previous CI 1.0 devices (new subscribers must observe some precautions depending on the broadcaster, e.g. be able to show the serial number of a certified recipient with a CAM-enabled smart card and, in the case of some cable broadcasters, the appropriate one Pay attention to the CAM firmware), provided that there is a CAM of the 1.0 standard for the stations to be received.
However, receivers with a CI + slot will prevent decryption if a previous CAM of the 1.0 standard is plugged in (provided that the respective transmitter has activated "Host Service Shunning", otherwise old modules of the DVB-CI 1.0 standard will also work).
Criticism of CI +
The developed specification is heavily criticized by consumer advocates. The CI + specification is often condemned as a paternalism and restriction of viewer rights. In 2009 the consumer advice center NRW recommended to potential buyers not to buy HD satellite receivers in order to avoid a bad investment due to the fast-moving market. The consumer advice center Rhineland-Palatinate warned against the viewer-unfriendly properties of the CI + technology against a technical incapacitation and considerable control of the television viewer.
The individual points of criticism are:
- Popular functions such as B. Fast forward during commercials or the transfer of recordings to removable media are denied. The content provider decides when which function is blocked.
- Customers are tied even more closely to a pay TV provider, as it is not possible to use different encodings (twin or multi-CAM). So that a customer z. If, for example, he can alternately receive Arena and Sky or ORF, SRF and SkyAT, he would have to change the CAM every time (or buy a receiver that has several CI + slots and can thus operate several modules in parallel).
- The use of DVB receivers is considerably restricted compared to the current CI 1.0 standard (see above)
- It is unclear whether the huge installed base of devices with the worldwide DVB-CI slot can be converted to CI-Plus.
- Due to the high hardware requirements and license costs, a CI + CAM costs more, and a new CI + -capable receiver is also required if a manufacturer does not offer a firmware update for the existing device. Recording from HD + channels is not possible with receivers retrofitted in this way.
- Multi-tuner solutions that enable the parallel reception of more than one program (e.g. recording and watching TV at the same time, picture-in-picture) can no longer be used, since no more than one program can be decrypted at the same time. If you use devices with several CI + slots and accordingly several CI + modules, you can bypass this restriction. In addition, with CI + version 1.4 “dual tuner support” is to be included in the specification.
- It is questionable whether PC-based TV recorders (e.g. Linux-based receivers and HTPC ) will receive CI + licensing, so that this product category could disappear from the market if CI + is successful. Reason: the re-encryption (see above) is intended to prevent the television content from e.g. B. can be tapped at USB, Ethernet, hard disk interfaces.
- Customers have to accept that their receiver or recorder can be excluded from CI + decryption by the trust center via signal transmission if the CI + security of the receiving device is no longer guaranteed (compromised). Except for the CI + functionality, the receiving device continues to work without any problems. Only with new firmware from the manufacturer, with which previous recordings would probably no longer be playable, could the affected receiving devices be used again for the decryption of CI + protected content.
Interests of those involved
Interests of the rights holder
Since the TV broadcast is re-encrypted on DVB recorders with CI + and can only be played on this device, the rights holders hope for better copy protection, i.e. H. a significantly lower digital transfer via the Internet, black copies etc. and thus lower sales losses.
Interests of the broadcaster and broadcasting stations
With better copy protection and the ability to record TV recordings from e.g. B. to prevent new films completely, the broadcasters and broadcasters gain a better negotiating position when buying film and television rights.
Cable network operators such as Vodafone Kabel Deutschland , Kabel BW , UPC Switzerland , Unitymedia and Tele Columbus have already announced that they will support the specification accordingly.
According to SES Astra , reception of the HDTV versions from RTL, VOX, ProSieben, Sat.1 and kabeleins, which have been offered via the new Astra HD + range since autumn 2009 and January 2010 , requires a CI + -compatible receiver. According to Astra, HD + can also be received via an HD receiver with a conventional CI interface; To do this, the HD receivers must be adapted by updating the firmware for HD + (this may deactivate or limit previous convenience functions). At the end of 2010, such updates were available for 100 devices from 19 manufacturers. Sky Germany (formerly Premiere) announced in September 2010 that it would also offer a CI-Plus module by Christmas 2010. In December 2010, however, it turned out that this was a time-limited offer in connection with new devices from a few manufacturers.
Since customers can receive broadcasts with CI + instructions with devices that still have the "old" CI slot, without restriction, broadcasters or broadcasters can only enforce a nationwide introduction of CI + if they
- switch to an encryption for which there are no CAMs according to the 1.0 standard.
- In the case of the HD + offer from Astra HD +, there are rumors that this type of encryption should be used.
- Broadcasters with an existing customer base would then not only have to replace all smart cards, but also all devices with CIs that were recognized in the past according to the 1.0 standard.
- In addition, manufacturers of CAM modules (mainly from the gray market) would undermine this measure if they offer such CAMs.
- Broadcasters with an existing customer base could provide new HDTV stations with a new encryption, so that they can introduce a CI + -capable receiver for customers who need a new receiver due to HDTV.
- Issue smart cards that only work in CI + specification CAMs. The attempt by Premiere (Sky) to introduce NDS Videoguard has shown that this is apparently difficult: Premiere / Sky must continue to offer Nagravision smart cards if the customer has a serial number of an existing device with a CI of the standard 1.0, e.g. B. that of a D-Box or a Premiere-certified CI-1.0-HD receiver.
Interests of the manufacturers
Manufacturers of televisions and set-top boxes, especially those with DVB-C receivers (digital cable television), who do not have their systems licensed by providers such as Sky, Kabel Deutschland , Unitymedia etc. at low cost and with functional restrictions , can use such devices so far only sold in smaller numbers. Reason: The providers refuse to take out a pay-TV subscription if an end customer cannot enter the serial number of a licensed device when taking out the subscription.
Now that most of the German-speaking cable network operators have announced their support for CI + (see above), CI + offers television manufacturers in particular the opportunity to sell devices with an additional DVB-C receiver and CI + -supporting CAM modules. The founding members of CI Plus LLP were all manufacturers of television sets who had no or hardly any DVB-C-capable end devices on offer in German-speaking countries.
In addition, larger manufacturers may recognize the opportunity for higher market shares in CI + by marketing CI + as an "innovation", so that consumers become insecure (fear of future incompatibilities of their current devices) and thus gain market share. The same applies to Kudelski / Nagravision / SmarDTV, the licensor of CI +.
A number of other consumer electronics manufacturers already support the specification or have announced it, e.g. B. Sony, Philips, Topfield, Loewe, JVC, LG, Panasonic, Samsung.
Manufacturers such as NDS (Videoguard encryption system), Irdeto, Neotion, SmarDTV or Smit now also offer CI + -compatible conditional access modules that can be used by some cable network operators (DVB-C, DVB-C2), satellite providers (DVB- S2, HD +) and pay TV channels such as Sky.
Interests of consumers
Compared to the normal Common Interface, CI + only offers technical disadvantages for consumers, some of which are listed above. There is only a theoretical chance of indirectly benefiting from the content providers' increased willingness to offer better content using this method.
Web links
- CI Plus website
- CI Plus Trustcenter website
- www.digitaltv-labs.com
- News on www.digitalfernsehen.de
- Report of the computer magazine c't about CI +
- Video on the situation at CI +
- Video contribution explaining the topic of CI to laypeople
- The truth about HD +
swell
- ↑ https://www.heise.de/ct/artikel/Abrechnung-mit-DVB-CI-291966.html
- ↑ DVB-CI-Plus Specification , accessed on April 10, 2019
- ↑ http://www.ci-plus.com/data/ci-plus_specification_v1.3.1.pdf
- ↑ High-definition television (HDTV): Buying the latest HD receivers is a bad investment . In: Consumer advice center NRW . July 16, 2009. Accessed on November 19, 2016. ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ Digital TV in HD quality: the consumer-unfriendly HD + strategy . In: Consumer Advice Center Rhineland-Palatinate . Archived from the original on January 7, 2013. Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved November 19, 2016 .; Press release from the Rhineland-Palatinate consumer center on CI +
- ↑ PDF with an overview of which functions are blocked for HD + customers , accessed on April 30, 2019
- ↑ http://www.digitalfernsehen.de/news/news_301911.html
- ↑ a b https://www.heise.de/newsticker/meldung/Humax-macht-alte-Receiver-per-Firmware-Update-HD-kompatibel-Update-7619.html
- ↑ [1] ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ https://www.heise.de/newsticker/meldung/Privatsender-wollen-Vorspulen-ueber-Werbung-bei-HD-verhinder-754177.html
- ↑ https://www.heise.de/ct/artikel/HD-hue-HD-hott-292198.html
- ↑ http://www.dvb.org/news_events/dvbscene_magazine/DVB-SCENE39.pdf
- ↑ Archive link ( Memento of the original from March 14, 2010 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ https://www.heise.de/newsticker/meldung/ProSiebenSat-1-HDTV-Neustart-mit-drei-Kanaelen-6849.html
- ↑ https://www.heise.de/newsticker/meldung/RTL-und-Vox-kuenftig-auch-in-HD-2-Update-220739.html
- ↑ http://www.hd-plus.de/#/hd-plus/news/einhund-empfangsgeraete , accessed on January 17, 2011
- ↑ heise online: Sky brings CI-Plus module by Christmas , September 6, 2010, access on January 17, 2011
- ↑ digitalfernsehen.de: Sky: CI-Plus-CAM initially only for selected new devices , accessed on January 17, 2011
