Taking the High Road: CSS Issues

Dr. Gregory B. Newby
School of Information and Library Science
University of North Carolina at Chapel Hill


Since December of 1999, the Motion Picture Association of America (MPAA) has been engaged in active litigation to prevent distribution of computer programs that enable DVDs to be played on computers without DVD software licensed through the DVD CCA(1).

This document addresses three areas of concern arising from this litigation:

Background: DVDs and the CSS

DVD stands for "digital versatile disk." This is similar technology to a CD-ROM, but DVDs hold far more data and include provisions for more functionality. The primary concerns of this document is the use of DVDs for distributing movies and other copyright-protected audio-video content. DVD players are shipped with many new computers, as an alternative to a CD-ROM(2). Standalone DVD players are available as alternatives to home VCRs.

CSS is the Content Scrambling System. This is an encryption technology that encodes the data on a DVD disc so it can be played back only with the right hardware and software. CSS insures that a DVD player is legitimate (e.g., not manufactured illegally), and that the program used to play back the DVD movie knows the correct encryption key to access the data. CSS also restricts playback for a particular DVD to a particular geographical region, so that DVDs encoded for region 1 (the U.S. and Canada), for example, could not be played back in region 3 (Mexico).

Copyright and Copying

A movie on a DVD may include several gigabytes of data. Using any DVD drive, the data may be copied to either another DVD (using a DVD-RAM writer) or to a hard drive, or transmitted over the Internet or another network.

CSS does not prevent or impeded this copying in any way. What CSS prevents is decoding the data so that it may be viewed. As an analogy, imagine having a piece of paper with writing in a language you didn't understand: you could copy the writing without knowing what it says.

The content of DVDs, like nearly all data stored in a tangible form, are copyrighted in the U.S. and elsewhere. CSS does not change this at all - people are limited from copying, selling, exhibiting or distributing the DVD content just as they are with other media such as books or videotapes.

Some parties (including the MPAA) have represented software enabling DVD playback that was not licensed by the DVD CCA as facilitating illegal copying of DVDs. This is simply not true: decryption is not a factor in copying DVDs with CSS.

Open Software

Many individuals and organizations produce software. Sometimes, the software source code, or its algorithms and processes, are made available for public use or scrutiny. This may be done under various types of license agreements, and usually does not mean the author gives up copyright protection(3).

The DVD CCA charges fees to license their DVD encryption software, restricts its use and distribution through an explicit license agreement, and does not make the software or process available to the public. It considers the encryption software to be a trade secret.

Because of the DVD CCA's licensing restrictions, software to play DVDs is not as widely available as DVD players. In particular, people who use Unix operating systems (such as Linux, FreeBSD, Solaris, etc.) may have a DVD player in their computer, but no software to decode DVD content. DVD software with decryption licensed by DVD CCA is available for Microsoft Windows and some other types of operating systems.

In October 1999, an anonymous group of programmers based in Germany developed a program that would decrypt DVD content on Windows or Linux computers without using software licensed from the DVD CCA. They developed the software by reverse engineering (that is, by studying how a licensed program interacts with the DVD, and replicating that behavior), and they were aided by both the weakness of the CSS encryption method and an error propagated by one of the DVD CSS licensees (a US-based company called Xing).

Reverse engineering is legal in many circumstances, and is how, for example, different companies can manufacture products that operate similarly without violating copyrights or trade secrets held by their competitors. Reverse engineering is almost definitely legal in the case of the German programmers. What they have done is to create a program with similar functionality to the CSS decryption software, but using independently derived methods.

The reverse engineered software is called DeCSS (for Windows) or css-auth (for Linux). These programs alone are not enough to play DVD movies. You also need various utilities to display the content, adjust the audio volume, etc. Utilities to support various types of video for Linux, including playing DVDs, are under active development and are available at http://www.linuxvideo.org.

The high road here is that programs that are developed through reverse engineering or other independent means, and interoperate with existing programs or data, are legitimate. The DVD CCA chose to employ relatively weak encryption, and to create a high barrier for entry to their licensing program.

The DVD CCA's choices resulted in law-abiding customers of the MPAA's products (DVD movies), who had purchased legal DVD players for their computers, being unable to play those DVDs unless they used software licensed by the DVD CCA. But such software is not available for a wide variety of computer operating systems, including Linux. DeCSS and css-auth, along with related utilities, provide a solution for this interoperability.

Fair Use

An important component of U.S. copyright law has to do with fair use. Fair use provisions enable educational institutions to use copyrighted materials in ways that would otherwise be prohibited, and ordinary citizens to make backup copies of various media.

The Digital Millennium Copyright Act of 1998 (DMCA, see an online version) added new provisions to copyright law that seem to supersede fair use, mostly in section 1201 of Title 17 of the United States Code (U.S.C.).

The opening paragraphs of section 1201 detail what constitutes fair use, and assigns responsibility to the U.S. Library of Congress to administer guidelines and provide feedback on the impact of prohibitions resulting from the DMCA. However, later sections appear to take away this opportunity for noninfringing activities, saying that any sort of technological access protection (such as encryption) removes the right to access the material except as specified by the copyright holder.

There are additional provisions for encryption research, for reverse engineering, and other permitted activities.

The bottom line is that the presence of any sort of access control "protection afforded by a technological measure that effectively protects a right of a copyright owner" removes fair use. Such protection is not limited to encryption - it may be that a simple click-through software license will be considered sufficient "protection."

The high road is to return to fair use. The right to utilize a legitimately acquired object for its intended use has been a hallmark of copyright and other areas of law. To give copyright holders a simple way to remove this right is against the intent and history of copyright, which instead has sought to balance the rights of the copyright owner with the rights of the public.

Benefits Lost

Technological opportunities today exceed those of any time in modern history. The DVD offers some exciting new opportunities, but they are being limited by the DMCA and the MPAA's legal activities.

Here are some things that DVD technology might enable, but are prevented or challenged by the DMCA or MPAA:

Copyright, including fair use provisions, has been effective at protecting the rights of copyright holders. In return, people who legitimately access copyrighted works have been able to benefit from these works in a variety of ways.

The high road is to trust to the existing provisions for fair use in copyright law, without providing unreasonable controls over fair use to copyright holders. Contrary to expectations of the MPAA in the 1980s, the availability of home VCRs did not result in a great increase in such things as sales of illegally copied videotapes. To the contrary, revenues from videotape rentals and sales frequently exceed box office revenues for movies.

The high road is to focus on what DVD technology makes possible, and to seek the most benefit we can achieve. The most benefit will not come from extreme restrictions on software to interact with DVD content.


DVD technology offers some outstanding capabilities, but the MPAA has chosen to employ aspects of the DMCA to limit people's access to these capabilities. The MPAA's legal suits against individuals involved with DeCSS and css-auth rely on one or more of these misunderstandings:

This document has attempted to examine some of the broader issues surrounding DeCSS and css-auth. Rather than focusing on exaggerated risks to the MPAA, we need to take a step back and consider the greater good that DVDs have the potential to offer. Rather than fearing what uses people might make of DVD technologies, it is in the interest of the public and the MPAA to enable a wide array of activities.

Encryption, open source and copyright are at an historic juxtaposition today. Through the DMCA, we have the potential to enter a dark age for fair use, where legitimate activities involving copyrighted materials are defined solely by copyright owners. In this dark age, persons who want to maximize the potential of new technologies by pursuing interoperability among computer components, adding functionality to software, or expanding public knowledge about the functionality of access controls, could be treated as criminals.

We also have potential to enter a new enlightened age. By setting aside the harsh restrictions the DMCA places on legitimate users of copyrighted materials, we can re-interpret fair use in the context of DVDs and other new technologies. We can seek a balance between the desires of copyright owners and their customers. We can let any programmer with ideas about how to expand our fair use of copyrighted content to share his or her ideas and software.

End notes

1. DVD CCA stands for the Digital Versatile Disc Copy Control Association. This is the organization that licenses software or software components that enable decryption of DVD content.

2. DVD players also play CD-ROM discs.

3. Software, like most other items stored in a tangible form, is automatically copyrighted in the U.S. unless it is the product of the federal government or explicitly granted to the public domain. Software may also be the subject of patents and other forms of legal protection.

Copyright (c) 2000 Gregory B. Newby. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation.