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Every element in a broadcast must have persistent and interoperable digital rights management (DRM) metadata through the creation/assembly/distribution/consumption chain. This is becoming increasingly more difficult as content is consumed on a wider variety of platforms.

Consider the lifecycle of media content. Actors, musicians, artists and writers produce various audio, video and graphic elements that are assembled into a program, disseminated and consumed. Tracking creator’s rights has yet to be facilitated through the complete content lifecycle.

Imagine in an interactive DTV world that there is a song or painting in a program that you, the viewer, would like to purchase. A T-commerce iTV implementation must transparently allow the viewer to click on an icon that designates an item to be purchased, order it and have it delivered while the rights holder automatically gets paid.


Too many people in broadcasting and the media business talk about DRM, but few seem to know exactly what copyrights protect.

Article I, Section 8, Clause 8 of the U.S. Constitution established the legal right of inventors and creators to financially exploit their creations. The Copyright Act of 1790 granted American authors the right to print, re-print, or publish their work for a period of 14 years and to renew for another 14. There have been major revisions to the act in 1831, 1870, 1909 and 1976.

Section 106 of the 1976 Copyright Act generally gives the copyright owner the exclusive right to do and to authorize others to do the following:

  • Reproduce the work
  • Prepare derivative works
  • Distribute copies of the work to the public
  • Perform the work publicly
  • Display the copyrighted work publicly
  • Perform the sound recording publicly by means of a digital audio transmission

The 1976 Copyright Act established the fair use of copyrighted material for criticism, comment, news reporting and teaching. Time shifting as fair use was established by a 5-4 vote in the Supreme Court in Sony vs. Universal City Studios, 1984. A generational slippery slope has lead to copyright anarchy. Some organizations claim that copyright inhibits technological innovation. Conversely, do patents inhibit creativity?

World gone digital

The Millennium Digital Copyright Act of 1998 has extended copyright to include new forms of digital delivery, in particular the Internet, and prohibits circumvention of copy protection technology. It also harmonizes U.S. copyright law globally by implementing two World Intellectual Property Organization (WIPO) treaties.

Another rewrite of copyright laws may be triggered by the recent effort by Google to digitize books in major libraries. This action has generated lawsuits by the Authors Guild and the American Association of Publishers. At issue is the requirement of obtaining a creator’s consent before scanning the work.

It’s in the bit stream

AES/EBU, SPDIF, MPEG/ATSC and AC-3 specifications define a one bit copyright flag. This has proved to be completely insufficient.

Controversy has surrounded the broadcast flag redistribution control descriptor (RCD) specified in ATSC A/65A. Although the FCC had mandated its use, the Supreme Court has ruled that the mandate is beyond the scope of the FCC’s legal jurisdiction. Congress is now reconsidering the issue.

Cable restricts content availability by using conditional access technologies in VOD and PPV. CableCARD technology provides copy protection for HDTV ready (tuner equipped) DTVs. In the future, downloadable conditional access systems (DCAS) will enable content protection without a CableCARD.

Rights management technology

The process of protecting and distributing content includes:

  • Authentications and key exchange. Full (never copy): Digital Signature Algorithm (DSA) or Diffie-Hellman (DH) key-exchange algorithm. Restricted (copy-1-generation): asymmetric key management and common key cryptography relies on shared secrets and hash functions.
  • Content encryption. A cipher algorithm is used to encrypt digital content. For interoperability, devices must support the cipher.
  • Copy control information (CCI). Encryption Mode Indicator (EMI), copy-freely, copy-never, copy-1-generation, no-more-copies. Embedded CCI, CCI is carried as part of the content stream.
  • System renewability. System Renewability Messages (SRM) are capable of revoking unauthorized devices. SRMs can be updated.

A content protection system (CPS) must be tamper resistant and the content delivery channel must be managed and protected. Content protection system architectures (CPSA) integrate existing technologies that address copy and playback control using watermark and encryption techniques.

Content and licenses are stored and delivered separately to the consumer. Content is encrypted before distribution using techniques that have been developed by the military, government and others (commercial). System stability is derived from the strength of the technologies, not from secret algorithms. Encryption prevents playback.

Licenses determine where content can be stored, how many times it can be played and the expiration date. A third-party licensing clearing house, the Digital Transmission Licensing Administrator (DTLA) issues keys and administers the content protection system.

Around the world in…

Even the sophisticated DRM methodologies of encryption and licensing are not enough to stop content pirates.

Watermarks are low bit rate information embedded in content, transparent to the end user and persistent. They cannot be removed. Un-encrypted content carries watermark CMI usage rules. Watermarks enable a forensic investigation to trace illegal copies back through the distribution chain and identify the guilty parties.

Standardization activity

Two large efforts are underway to standardize DRM metadata. MPEG 21 is working to unify rights data persistence by using a Rights Expression Language (REL) that facilitates interoperable metadata, while Microsoft offers a comprehensive DRM suite.

The recent SMPTE conference in NYC devoted a half-day session to copyright and DRM topics. Various presenters described the primary issues:

  • Interoperability of DRM technologies is a major impediment to the networked home.
  • The necessity to be able to trace rights from consumption back up the distribution, origination, creation chain. Failure to accomplish this will stifle business models and impact potential revenue.
  • Proprietary monetary systems vs. open free DRM standards

Legal liability

Broadcasters are not in the business of illegally distributing copyrighted material. But are broadcasters required to pass DRM data? If so, DRM metadata persistence becomes a legal matter. If they fail to do so, are they liable for copyright infringement?

Media asset management (MAM) systems can incorporate rights management. Is a traffic light alert sufficient? Content goes to air, worry about the rights later. That’s a bad idea if it may cost you $100,000 or more for a willful copyright violation. Or do you take a cautious approach and restrict MAM publication of material without rights clearance and inhibit the production process?

At home

The accelerating emergence of home digital networks exacerbates the need for DRM technologies. Transparent interoperability across devices is required or the consumer may not feel that a media center PC/server is worth the trouble. The Digital Living Network Alliance (DLNA) seeks to insure operability of DRM implementations across platforms.

High-bandwidth digital content protection (HDCP), intended for networked consumer devices, seeks to solve the consumer device interoperability problem. Both the DVI and HDMI interface specifications use HDCP.

Think twice

Educating the consumer as to the rights of creators is important. Many are not aware that they are doing something illegal.

DRM technologies must not disable or damage consumer equipment. And most importantly, the terms and restrictions on fair use of purchased content must be clearly stated and agreed to prior to initiating a transaction.

So before you do your next presentation, think about the image you downloaded from the Internet or running that internally produced corporate DVD at a convention. Do you really have the right to use the content in this manner?

Article References

Copyright Suit Filed Over Thomas Friedman Book Cover, Editor & Publisher

How Hollywood has been trying to Disrupt Disruptive Innovation, Fred Von Lohmann, Electronic Frontier Foundation;jsessionid=YYOKD4CVVCHX4QSNDBGCKH0CJUMEKJVN

Will the Online Book Publishing Flap Rewrite Copyright Law?, Wharton

Content Protection for Recordable Media (CPRM) and Content Protection for Prerecorded Media (CPPM) specifications and licensing information

Windows Media 10 DRM (opens in new tab)

The MPEG 21 Rights Expression Language, Rightscom

Are You a Copyright Criminal?, Dave Zielinski, 3M Digital Transmission Content Protection White Paper



Library of Congress, Copyright Office

World Intellectual Property Organization

The Digital Library Foundation

Electronic Frontier Foundation

Copyright Legal History