The Content Scrambling System Does Little To Prevent Pirating of DVDs
We recently ran a story here at Cryptonomicon.Net reporting on the acquittal of 'DVD-Jon' Johansen ('DVD Jon' Acquitted A Second Time.) In reviewing press coverage of this story, we have been somewhat dismayed by reporters' understanding of technical issues surrounding DVD piracy. Specifically, we would like to go on record and take issue with the statement in the Associated Press's story on the subject (mirrored here at the San Jose Mercury News.) Towards the end of the article, the following paragraph attracted our attention:Johansen's program is just one of many that can break the CSS, which prevents illegal copying and blocks the use of legitimate copies on unauthorized equipment.
The statement seems to imply that CSS can block all types of content piracy. While we acknowledge that had CSS been a competently designed cipher and used in equipment that implemented even the most basic key management primitives, it could have prevented some forms of piracy. The simple fact of the matter is that if a large-scale media piracy organization wanted to mass produce direct copies of DVD disks, the DVD-CCA's Content Scrambling System (CSS) does nothing to prevent it.
The Content Scrambling System, which is the algorithm "cracked" by Johansen's DeCSS code, uses one of several relatively well-known keys to "encrypt" the contents of digital video and audio streams on DVDs. But CSS is applied at a level "above" the physical media where lands and grooves on the DVD surface are used to represent 0's and 1's. Video pirates who wish to make illegal copies of DVDs can do so simply by reading the encrypted bit stream off of a reference disk, and writing the same bit stream back on to fresh new blank DVD. Well funded piracy operations could likely afford the same equipment used to "press" DVDs as is used by legitimate entertainment industry manufacturers. More cost conscious piracy rings could use DVD-R technology.
So what does CSS protect?
Though we believe that the entertainment industry spokes people are stretching their credibility when they assert that programs like DeCSS contribute directly to the $3.0 billion market for pirated DVDs, this is not to say that CSS is completely without merit. One aspect of video piracy that CSS can offer some protections for is the direct digital conversion from DVD to Video CD format. From a piracy perspective, this is a valuable commodity. Video CDs may be manufactured for a fraction of the cost of DVDs, and can be played in many commercial DVD players. Video CDs offer slightly lower picture quality and can offer poorer sound quality, but do you think this will deter customers of the Video pirates?
But to say that CSS prevents the copying of DVDs to VideoCDs is not entirely true. It prevents the direct digital transfer, but video pirates have shown time and time again that they are perfectly willing to re-digitize the analog output of a DVD player. More likely the pirates will simply place a video camera in front of the TV screen playing the video and then digitize the output of the video camera. Can CSS be used to stop this type of copying? Absolutely not.
CSS is useful for one thing, however, and that is ensuring that DVDs can be played only on Windows and Macintosh computers. Why are these models so important? Likely because they are commercial operating systems and the entertainment industry can extract a reasonable revenue stream from Microsoft and Apple customers; a revenue stream that would be difficult to collect for Debian or FreeBSD users. (These operating systems are generally not "sold." As there is no financial transaction involved in downloading these free operating systems, the DVD-CCA cannot extract a royalty payment.)
No doubt some readers will consider this article an apology for video piracy. Far from it. Video piracy (like software piracy) is a crime. Pirated DVDs and Video CDs are routinely of lower quality than the original. While it's easy to point the finger at the motion picture and recording industry practices and claim, "none of the money goes to the artists!" That's still not a good justification for stealing. Though Cryptonomicon.Net does not syndicate it's content for a fee, we do assert copyright ownership of the contents of this site. We would be very cross should someone "pirate" our site, and for that reason believe that entertainment companies have every right to copyright their works and expect to earn revenue from the fruits of their labors.
We do, however, encourage fair use of our articles and link farm. And it is the exact meaning of the term "fair use" that's key here. If I buy a DVD, what exactly am I buying? Am I buying the media? Am I buying the content? Or maybe I'm buying a license to view the content? Is it moral or legal for the entertainment industry to dictate what equipment I may use to play my DVD? These are the legal questions that are being hashed out in the Norwegian courts. Two decisions from the courts in Norway do not legitimize piracy. They re-affirm the right of individuals (or at least the right of Norwegian individuals) to choose the platform on which they will view their DVDs.
Confusing the issue and accusing the Norwegian court of legitimizing piracy is nothing but FUD: Fear, Uncertainty, and Doubt.
