ITU-R REPORT BT 2070-1-2009 Broadcasting of content protection signalling for television《保护电视信号发送内容的广播》.pdf

1、 Report ITU-R BT.2070-1(11/2009)Broadcasting of content protection signalling for televisionBT SeriesBroadcasting service(television)ii Rep. ITU-R BT.2070-1 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequency sp

2、ectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional Radiocommunicati

3、on Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be used for the submission of patent stat

4、ements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found. Series of ITU-R Reports (Also availabl

5、e online at http:/www.itu.int/publ/R-REP/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermination, amateur and related satellite ser

6、vices P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management Note: This ITU-R Report was approved in English by

7、 the Study Group under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2010 ITU 2010 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rep. ITU-R BT.2070-1 1 REPORT ITU-R BT.2070-1 Broadcasting

8、 of content protection signalling for television (2006-2009) 1 Introduction This Report comprises a report on the current “state of the art” of digital content protection for broadcast television and related services. Recent rapid evolution in the nature of consumer use of broadcast and internet ser

9、vices has changed many of the old assumptions made by broadcasters and television equipment manufacturers. Television broadcasts can now be easily recorded using high-capacity personal video recorders (PVRs), and this content can now be shared with others over high-speed internet connections or by b

10、urning to high-capacity removable media such as DVDs. Old assumptions that a set-top-box connects to a single, display-only, television set are fading fast. Consumers are increasingly aware of alternative ways to enjoy broadcast content, and are always looking for newer and more rewarding experience

11、s. Accordingly, there is an urgent need for content owners and broadcasters to balance the need to protect their investment with potential loss of acceptability to an educated and technically knowledgeable user community. 1.1 Background Working Party 6M (WP 6M) has determined that a compendium of in

12、formation should be disseminated and carried forward in preparation for a Report on this subject area. Building upon the initial work of previous meetings of WP 6M, it was determined that in order to develop principles which can safeguard the interests of broadcasters and the public in copy protecti

13、on signalling for television, a number of topics need to be addressed. To this end, WP 6M has begun to develop a content protection model as described below. Radiocommunication SG 6 Recommendations for content protection need to address the requirements identified for each of the reference points an

14、d subject areas identified in the model. The administrations attending WP 6M concurred that this new area of applying security to broadcast material presents challenging topics, and thus great care and deliberation must be taken in creating Recommendations. Further information in accordance with the

15、 work programme will be gathered. 1.2 Sources This Report was prepared based on a number of past input documents provided to Radiocommunication WP 6M, and on public documents and materials suggested to the Rapporteur. 2 Rep. ITU-R BT.2070-1 1.3 Working method At the April 2005 meeting of WP 6M, it w

16、as agreed that the total aggregate volume of contributions on this subject was too much for a simple report. The Rapporteur was therefore requested to produce a “digest” report summarizing the issues and solutions described in the various submissions. As such, this Report is now intended to summariz

17、e what WP 6M has learned so far in this process. Many of the submissions are mentioned explicitly in the text below, while others have been considered without an explicit reference. The Rapporteur now anticipates a period of consideration for future direction, along with comments made against previo

18、us and current text in this Report. This remains a “living report” which will evolve over time, and nothing contained herein constitutes finalized or formally agreed text. 2 The threats to the industry This section describes some of the commercial threats to broadcasters and content providers result

19、ing from advances in technology. However this list is not exhaustive. 2.1 Commercial piracy Commercial reproduction of broadcast material includes the mass production of DVD versions of movies and television series, and the sale of content through unlicensed internet services. It may also include th

20、e sale of technology (or advertising therein) that is clearly intended to promote piracy although the software vendor does not directly profit from the act of piracy. 2.2 Casual piracy This includes consumers who make single copies of movies and other content as gifts for friends or family members w

21、ith no intent for personal gain. Recent research indicates that most consumers feel this is normal and inevitable activity, though it remains a potential violation of copyright law. 2.3 Region leakage For some content, broadcasters negotiate the right to transmit based on geographical coverage. Thes

22、e agreements typically allow for a certain amount of leakage, e.g. across terrestrial broadcast boundaries. However, excess leakage for other broadcasters (via internet, satellite footprint or otherwise) can reduce the value of that content for other broadcasters. NOTE 1 This effect is unrelated to

23、DVD region coding, and is perhaps most noticeable for content with a very short commercial lifetime such as sporting coverage. 2.4 Early window viewing Often related to region leakage, this involves audiences having access to content while it is meant to be restricted to another format. For example,

24、 being able to obtain DVDs while a movie is still in local theatres, or seeing content from a foreign free-to-air broadcast while it is only available on pay-per-view in the local market. The effect of early opportunities for viewing is to reduce the revenue potential for existing legitimate license

25、es of the content, as the potential market shrinks. Rep. ITU-R BT.2070-1 3 2.5 Loss of advertising revenue Services that depend on advertising for some or all of their revenue are vulnerable to loss of revenue from any of the above effects, or as a result of advertisement-skipping. However, most con

26、sumers feel strongly that they have a right to avoid adverts they find annoying, whether for products they dont want or need, or for products they find distasteful to think about. As always, a balance needs to be struck. 2.6 Derivative works With todays ease of capturing and editing material, there

27、is a growing risk of copyright works being reused and adapted without permission. For example reusing a soundtrack for another purpose, or developing an unofficial re-edited version of a movie beyond the bounds of permitted fair use. 2.7 Poor implementations Where content protection is mandated, the

28、re is a threat to compliant device manufacturers from competing products that do not meet the same standards of protection. The usual “market will choose best implementations” actually runs in reverse for content protection, where often the (informed) consumer will choose the least secure implementa

29、tion if it provides a perceived greater ease of use or flexibility. As evidence of this in other markets, readers should consider the relative attractiveness of DVD players that ignore the DVD region code (which are now commonly available in many countries), or cell-phones that are “unlocked” from t

30、heir original (subsidizing) service provider. Indeed, DVD region coding has recently been declared anti-competitive, and therefore illegal, by the European Commission. 3 The challenges for legitimate use Balancing the fears of content providers arising from the threats noted above, there are a numbe

31、r of corresponding fears over excessive corporate control of consumer use of broadcast television services. Throughout the industry there is considerable debate over the technical sensibility of providing both adequate protection and flexibility of use to consumers for the same item of content. 3.1

32、Legitimate fair use In many countries, there are historical principals of fair use that are recognized in legislation or common law. These vary greatly between jurisdictions, so there are no hard-and-fast rules for what should be allowed. Some of these are not well solved through use of technology (

33、such as expiry of copyright material into the public domain), but blocking certain other rights may result in consumer complaints, regulatory restrictions, or legal challenges to content protection technologies. The digital media project (http:/www.chiariglione.org/project/) has attempted to identif

34、y a number of “traditional” rights consumers associate with content they “own” in todays world of television and digital media. How applicable these traditional rights are in the world of rapidly evolving technology is a subject of intense debate. 4 Rep. ITU-R BT.2070-1 3.2 Accessibility Of specific

35、 interest are the traditional rights employed by those working to assist people with various disabilities, for example the RNIB (http:/www.rnib.org.uk) and RNID (http:/www.rnid.org.uk/) who are very active in UK policy making. 3.2.1 Application usability As television becomes increasingly interactiv

36、e, there is a risk that some of the audience will be denied access to content due to inability to use some of the interactive applications that make it available. For example, content protection mechanisms that complicate the user interface may become awkward for users with limited vision. 3.2.2 Add

37、ition of subtitling and descriptive audio Examples include volunteers adding descriptive audio to television shows for the visually impaired, or overlaying signing for the hard of hearing. The modified shows would then be made available to the relevant community. Both of these examples can be hamper

38、ed by content protection technology, leaving those groups entirely dependent on the timely delivery of these features by the original content producers. This is further complicated for those who rely on subtitling for less common languages. 3.3 Education and academia It is a traditional right of aca

39、demia to employ extracts of copyright works of many kinds for use in academic study, criticism, or as teaching materials. Content protection technology can make this onerous or impossible. 3.4 Public service obligations Some broadcasters are bound by public service obligations such that content they

40、 transmit must be made available to all legitimate users without any technical barrier. In such cases it is often unlawful to require any form of subscription to the service the user is already recognized as a subscriber because they live in the territory and pay the relevant license or tax, so they

41、 already have right of access to this content which cannot be denied by the broadcaster. 3.5 Open source software Content protection technology often depends on some form of trust model, with some degree of robustness in the device before it is trusted with valuable content (see 5.2.2). However, tho

42、se companies and individuals adhering to the strict principles of open source software may be unable to prove robustness, as their software can be changed by anyone using the provided source. There is therefore a fear that this community will be forever denied access to broadcast television content

43、despite the innovations they might be able to contribute to the industry. Others will contend that open source software is inherently insecure and as such is an inherently unacceptable development methodology for systems that must protect content. Both camps have some strong proponents. Rep. ITU-R B

44、T.2070-1 5 3.6 Public domain material In some territories there is fear that content which is already in the public domain could become over-controlled by making it available under broadcast content protection, thus denying by technological means the legitimate rights that users have with public dom

45、ain material. Some broadcasters fear legal exposure if accused of this. 3.7 Creative commons A recent innovation in the publication of content is the use of creative commons licenses. These allow for the non-commercial creative reuse of the labelled content, provided that the original author is cred

46、ited. This approach is attractive for smaller content providers such as independent artists and authors, as it allows their work to flow and become far more visible. A variant of creative commons allows for commercial use by residents of developing nations. Some major broadcast organizations are now

47、 adopting creative commons as a means to give consumers and other content creators access to their archival materials in a useful manner. 4 Architectural model Content protection for broadcasting is a very complex subject, and many well-known proposals solve only part of the bigger puzzle. Radiocomm

48、unication WP 6M will therefore use the following model to identify areas of study. FIGURE 1 WP 6M content protection model Rep 2070-01R1 R2 R3R3 R5R4BroadcasterContentContent protection signallingAcquisitorpointWirelessofwired homenetworkDeviceDeviceDeviceDeviceDisplay / speakers(consumptior)Exportt

49、o othersystemsWith this diagram we define a set of reference points at which requirements and/or solutions need to be defined. Some of the terminology used is based on the DVB (http:/www.dvb.org) CPCM concepts. The following diagram further breaks down these reference points into topics for consideration or study. 6 Rep. ITU-R BT.2070-1 FIGURE 2 Expanded reference points Rep 2070-02R1.1.1: TerrestrialR1.1.2: SatelliteR1.1.3: CableR1.1.4: MobileR1.1.5: IPTVR1.1: Broadcast technologyR1.2: Content typeR1.2.1: Clear-to-airR1.2.2: EncryptedR1.2.1.1: Public serviceR1.2.1.2: Commerci