Digital rights management

Digital Rights Management (DRM)1 is an umbrella term referring to any of several technical methods used to control or restrict the use of digital media content on electronic devices with such technologies installed. The media most often restricted by DRM techniques include music, visual artwork, and movies. Some digital media content publishers claim DRM technologies are necessary to prevent revenue loss due to illegal duplication of their copyrighted works. Civil libertarians, in contrast, argue that transferring control of the use of media from consumers to a consolidated media industry will lead to loss of existing end-user rights, as well as stifling innovation in software and cultural productions. No current DRM technology includes a mechanism to enable fair use rights per se, though some DRM methods allow acts of copying which may coincidentally align with legal use rights. Arguably, a technology cannot, in principle, know what legal restrictions and rights apply in a specific jurisdiction, usage context, under an external contract, or to an individual author, owner, or publisher.



Digital Rights Management, as its name implies, applies only to digital media. Digital media have gained in popularity over analog media both because of technical advantages associated with their production, reproduction, and manipulation, and also because they are sometimes of higher perceptual quality than their analog counterparts. Since the advent of personal computers, digital media files have become easy to copy an unlimited number of times without any degradation in the quality of subsequent copies. Many analog media lose quality with each copy generation, and often even during normal use. The popularity of the Internet and file sharing tools have made the distribution of copyrighted digital media files simple.

The unauthorized availability of multiple perfect copies of copyrighted materials is perceived by much of the media industry as a threat to its viability and profitability, particularly within the music and movie industries. Digital media publishers typically have a business models that rely on their ability to collect a fee for each copy made of a digital work, and sometimes for each performance of said work. DRM was created by and/or designed for digital media publishers as a means to allow them to control the duplication and dissemination of their content.

Although technical control measures on the reproduction and use of application software have been common since the 1980s, the term DRM usually refers to the increasing use of similar measures for artistic works/content. Beyond the existing legal restrictions which copyright law imposes on the owner of the physical copy of a work, most DRM schemes can and do enforce additional restrictions at the sole discretion of the media distributor (which may or may not be the same entity as the copyright holder).

DRM vendors and publishers coined the term digital rights management to refer to the types of technical measures discussed here. Because the "rights"—actually, technical capabilities—that a content owner grants are not necessarily the same as the legal rights of a content consumer, DRM critics maintain that the phrase digital rights management" is a misnomer. To these critics the term digital restrictions management is a more accurate characterization of the functionality of DRM systems.

An oft-cited example of DRM overreach is Adobe Systems' release in 2000 of a public domain work, Lewis Carroll's Alice in Wonderland, with DRM controls asserting that "this book cannot be read aloud" and so disabling use of the text-to-speech feature normally available in Adobe's eBook Reader.

Legal enforcement of DRM

DRM controls are sometimes proposed to be enforced through so-called trusted computing. However, civil libertarians maintain that trusted computing creates the prospect of a computer system which cannot be trusted by its owner, but rather its behavior can be remotely manipulated at any time, regardless of the legal merits of such manipulation. Most opponents have little faith that the courts or legislatures will be able to limit such manipulation to only that which is legally permitted.

Several laws relating to DRM have been proposed or already enacted in various jurisdictions (State, Federal, non-US). Some of them will require all computer systems to have mechanisms controlling the use of digital media. (See Professor Edward Felten's freedom-to-tinker Web site for information and pointers to the current debate on these matters).

An early example of a DRM system is the Content Scrambling System (CSS) employed by the DVD Forum on movie DVD disks. The data on the DVD is encrypted so that it can only be decoded and viewed using an encryption key, which the DVD Consortium kept secret. In order to gain access to the key, a DVD player manufacturer was required to sign a license agreement with the DVD Consortium which restricted them from including certain desirable features in their players, such as a digital output which could be used to extract a high-quality digital copy of the movie. Since the only market hardware capable of decoding the movie was controlled by the DVD Consortium, they hoped to be able to impose whatever restrictions they chose on the playback of such movies. See also DIVX for a more restrictive and less commercially successful variant of this scheme which is no longer marketed. That name is also used (DivX), in ironic tribute to the defunct disk "protection" scheme, for an implementation of the MPEG-4 video compression protocol.

To date, all DRM systems have failed to meet the challenge of protecting the rights of the copyright owner while also respecting the rights of the purchaser of a copy. None have succeeded in preventing criminal copyright infringement by organized, unlicensed, commercial pirates. Flaws of some well known systems include:

  • Physical protection: Utilizes separate hardware to ensure protection. Examples include hardware dongles that had to be attached to the computer prior to using the content, and USB and smart card devices working in a similar fashion. Physical protection methods consistently failed in consumer markets due to compatibility problems and extra level of complexity in content use; however, they did enjoy limited success with enterprise software.
  • DIVX: Required a phone line, inhibiting mobile use. To take a work for which unlimited plays had been purchased (called DIVX Silver) to a friend's home, it was necessary to carry a 30 lb DVD player as well as the light and compact disc; or to telephone the DIVX service and have the player of the friend transferred to the account of the purchaser of the work, and then call again to have it switched back. The system prevented certain legal uses such as the creation of compilations, by the purchaser. The system also prevented the sale or lending of purchased works, by recording the account information of the original purchaser on the DIVX Silver disk. Under copyright law, the owner of a legally-obtained copy of a work may create compilations, or re-sell the copy in the secondary (used goods) market. By using these technical measures, the DIVX system was able to thwart the buyer's right of first sale and other fair use rights. DIVX is a form of physical protection of the content (see above).
  • CSS: Restricts the ability to buy DVDs in one country and play them in another, because CSS is also used to enforce Region Coding. It restricts fair use and first purchaser rights, such as the creation of compilations or full quality reproductions for the use of children or in cars. It also prevents the user from playing CSS-encrypted DVDs on any computer platform (notably Linux computers). Recently, with the advent of DeCSS and cryptographic analysis of the CSS algorithm have demonstrated flaws in this system which can be exploited to allow users to recover some of their fair-use rights. Full quality digital copies can now be easily made, making fair use by normal consumers easier. Although it has been argued that programs like DeCSS make copyright infringement easier, this system has never been effective in preventing illegal mass copying of DVDs by criminal gangs, even before the system was found to be flawed. CSS is an example of certificate-based encryption.
  • Product activation: Invalidates or severely restricts a product's functionality until the product is registered with a publisher by means of a special identification (activation) code. The process often uses information about the specific configuration of the hardware on which the software runs, hashing it with the identification number specific to the product's license. Microsoft was the first company to utilize this method in its Microsoft Reader product. Activation was later used with Windows XP and then with Office XP. Ultimately, workarounds which bypassed the product activation system have been developed. In 2003, Intuit's use of a flawed product activation scheme angered thousands of customers who were denied legitimate use of the product, resulting in a formal apology by Intuit and discontinuation of the use of the mechanism.
  • Digital watermarking: Allows hidden data, such as a unique disc ID, to the media. The name and address of the purchaser would be taken at the location of sale, and entered into a database along with the unique media ID. This does not prevent copying, but it ensures that any copies made of the media will bear the same hidden information - So if the content appeared on (for example) P2P networks, the ID number could be easily extracted and the purchaser prosecuted. This is not technically DRM, as it does not allow direct control over the use of the media.

Digital Millennium Copyright Act

The controversial Digital Millennium Copyright Act was passed in the United States in an effort to make the circumvention of DRM systems illegal. It was passed without debate, and without even token opposition, Congress being apparently under the impression that it was a "technical" enactment, without significant public policy implication. It has been widely imitated elsewhere by other governments.

Despite the passing of this law, which has since received substantial opposition on Constitutional grounds, it is still relatively easy to find DVD players which bypass the limitations the DVD Consortium sought to impose. John Hoy, president of the DVD Copy Control Association, in testimony to the Library of Congress in 2003 stated "furthermore, if a consumer in the United States desires to view a DVD disc that has been region coded only for Europe, then that consumer is free to purchase a DVD player (either hardware or software) that is coded to play European DVDs. No legal restrictions apply – either through the CSS license or otherwise – to the importation and use of non-U.S. region players in the United States". (reply comments, comment 28, page 4, PDF document (

There has been a widely publicized arrest and arraignment of a Russian programmer, Dmitry Sklyarov, for violation of the DMCA. He did the work cited for his employer, Elcomsoft, while in Russia, where it was and remains entirely legal. The product allowed those who were in possession of a password, presumably lawfully obtained along with the encrypted copy of the work, to make copies without encryption locking them to use on a single computer. Sklyarov was arrested on a criminal warrant during a lecture visit to the US, and spent several months in jail until a compromise was reached. The ensuing criminal case against Elcomsoft (for whom Sklyarov did the work) resulted in acquittal. See Professor Edward Felten's freedom-to-tinker Web site [1] ( for some observations on the DMCA, its proposed successors, and their consequences, intended and unintended.

The DMCA is also causing a chill in the activities of fully legitimate computer scientists. Professor Felten, of Princeton, has had difficulty publishing papers he and his students have written; they were related to a contest sponsored by a security software company inviting investigation of a product design. (See Internet postings in Felten v. RIAA). Alan Cox, the Englishman who was Linus Torvalds' chief deputy throughout almost the entire first decade of the development of Linux, has resigned his position due to his concern that a criminal charge might be laid against him as a result of some code in the Linux kernel. He has even declined to post explanations of some changes made in the kernel (the changelog is fundamental to the project) because of his concern about his exposure to prosecution and penalty under the DMCA; such explanations might be seen as a DMCA "disclosure". He has also declined to attend US software conferences for similar reasons. Niels Ferguson, a Dutch cryptography expert and security consultant, discovered a flaw in an Intel security protocol, told Intel about it and was told that Intel had no objection to his publishing a paper about the problem. He has nevertheless decided not to publish due to concern about being arrested under the DMCA.

New and even more controversial DRM initiatives have been proposed in recent years which could prove more difficult to circumvent, including copy-prevention codes embedded in broadcast HDTV signals and the Palladium operating system. A wide variety of DRM systems have also been employed to restrict access to eBooks. See the TCPA/Palladium FAQ [2] ( maintained by Cambridge Professor Ross J. Anderson for a clear discussion of two prominent proposals.

Opponents of DRM, as envisioned and as currently implemented, note that by delegating control of computer access (or control of the ability to execute some programs, or to execute programs only with certain data) to anyone except the user and the machine's administrator(s), there is a very considerable risk of problems caused by such third party interference which go well beyond the enforcement of copyright.

For instance, due to a bug (or misdesign, or misadministration of an otherwise "reasonable" design) the control software (eg, in a trusted computing system) implementing the local part of a DRM scheme may prevent a computer user from using his computer at all, or from using programs (or using data as an input to a program) when such use is actually completely legitimate and not a violation of any copyright holders' rights. Or, for another example, a legally obtained copy of a DVD might be blocked because it is being used on equipment which doesn't include the DRM function permitting access to it, or which if included, doesn't interoperate correctly. Currently, DVDs legally purchased in some places are not playable in other places for exactly these reasons, although in this case it is marketing considerations, and not "security", which is the reason for the restriction. DRM provisions have already appeared in released versions of some Microsoft Windows operating system subsystems (e.g., Windows Media Player) and are scheduled in more as Palladium is implemented in currently planned, not yet released, versions of Windows.

Security protocols, software implementing security protocols, and cryptography have historically proven extremely difficult to design without vulnerabilities due to bugs or design mistakes. This has been true of designs from experienced and well respected professionals; the record is abysmally poor for those inexperienced in cryptography and security protocols.

Other copyright implications

While DRM systems are ostensibly designed to protect an author's right to control copying, this protection is only half of the bargain between the copyright holder and the state. The other half of the bargain is that after a statutorily-defined period of time the copyright work becomes part of the public domain for anyone to use freely. DRM systems currently employed are not time limited in this way, and although it would be possible to create such a system (under compulsory escrow agreements, for example), there is currently no mechanism to remove the copy control systems embedded into works once they enter the public domain, after the term of copyright expires.

Furthermore, copyright law does not restrict the resale of copyrighted works (provided those copies were made by or with the permission of the copyright holder), so it is perfectly legal to resell a copyrighted work provided a copy is not retained by the seller—a doctrine known as the first-sale doctrine in the US, which applies equally in most other countries under various names. Similarly, some forms of copying are permitted under copyright law, under the doctrine of fair use (US) or fair dealing (many other countries). DRM technology restricts or prevents the purchaser of copyrighted material from exercising their legal rights in these respects.

Moreover, the scope of legal rights cannot, in principle, be fully encoded in technical access/copying restrictions. For example, a photograph generally falls under the copyright of its photographer, and may not be reproduced in an unlimited way by other persons. A photographer wishing to enforce her copyright might attach some DRM codes to a digital version of her photograph that indicate "may not be copied." However, the photographer might subsequently sign an agreement with another party authorizing such duplication (either for monetary payment, or to serve some other public or private purpose). Under law, the moment such an agreement is signed, copying (under the terms set forth) becomes legal; but the DRM software cannot know that people with pens affixed their name to the contract, and thereby changed legalities.

DRM has been used by organizations such as the British Library in its secure electronic delivery service to permit worldwide access to substantial numbers of rare (and in many cases unique) documents which, for legal reasons, were previously only available to authorized individuals actually visiting the Library's document centre at Boston Spa in England. This is an interesting case where DRM has actually increased public access to restricted material rather than diminished it.

DRM advocates

Some DRM advocates have taken the position, in essence, that DRM / security / cryptography design goals and operational contexts are sufficiently well understood, and that software engineering is also sufficiently well understood and will be so practiced, that it is already possible to achieve the desired ends without causing unrelated problems for users, their computers, or those who depend on either. In essence, they claim there is no technical nor engineering competence problem foreseeable with such software.

Others have taken the position that creators of digital works should have the power to control the distribution or replication of copies of their works, and to assign limited control over such copies (e.g. creative commons license). Without the power to do these things, they argue, there will be a chilling effect on creative efforts in the digital space. DRM is one means by which they may obtain such power.

DRM advocates further believe that DRM opponents advocate hardware- and media-owner rights at the expense of copyright-owner rights. Consumers of hardware and media voluntarily and knowingly agree to the grant of limited use of the content exhibited using their physical media.

DRM opponents

Many organizations and prominent individuals are opposed to DRM in its various currently proposed forms. Two notable opponents are John Walker in his article, The Digital Imprimatur: How big brother and big media can put the Internet genie back in the bottle[3] (, and Richard Stallman in his article/story The Right to Read ( Professor Ross Anderson of Cambridge University heads a British organization which has been quite active in opposing DRM and similar efforts in the UK.

The Electronic Frontier Foundation and similar cyber civil rights organizations, including, also hold positions which are characterized as opposed to DRM.

Techno-liberals such as FFII criticize DRM's impact as a trade barrier from a free market perspective.

The use of DRM may also be a barrier to future historians, since technologies designed to permit data to be read only on particular machines may well make future Data Recovery impossible - see Digital Revolution. This argument connects the issue of DRM with that of asset management and archive technology.

The use of DRM is a key part of implementation of corporate compliance policies such as the Sarbanes-Oxley Act of 2002, protecting corporate documents from unauthorized tampering and creating an audit trail which can be used to determine liability at board level within corporations for misdemeanors. This level of control is obviously unwelcome at certain levels.

DRM opponents argue that presence of DRM infringes private property rights and criminalizes a range of activities now perceived by the users as normal. The DRM component takes control over the rest of the user's device which they rightfully own (e.g. MP3 player) and restricts how it may act, regardless of the user's wishes (e.g. preventing the user from copying a song). All forms of DRM depend on the device imposing restrictions that cannot be legally disabled or modified by the user. In other words, the user has no choice.

Controversies about and consequences of deployed DRM

Several DRM schemes have now been implemented. DRM opponents have seen many of them as "abuse" of copyright (called eSlavery in Europe); DRM proponents have seen them as a reasonable balance of consumer concerns and artist rights. Examples include:

  • Digital imprimatur
  • inclusion of commercials on the "unskippable track" on DVDs reserved for the copyright notice;
  • using the DMCA to protect items that do not qualify for copyright protection, such as garage door openers and printer ink cartridges;
  • adding restrictions on reading books aloud in the EULA of eBooks;
  • using copy control schemes to thwart the existing exceptions to copyright (e.g. fair use);
  • who shall hold the keys to ancient literature, music and other works which has always been part of, has passed over, or will pass over to the public domain this year or the year after that?
  • the possibility of dominant DRM-inclusive recording and playback technology being used uncritically by users unaware of the dangers and consequences thereof, and potentially later locking them out of their own creations; this already happened with SCMS in consumer-grade DAT equipment
  • preventing academic publication and distribution of information relating to flaws in computer security in the absence of said technologies' creators' permission
  • silencing individuals who have found serious flaws in software used in electronic voting;
  • restriction of medical records and personal financial information using DRM to protect consumer rights. Insurers, lawyers and loan companies have strongly objected to the use of these technologies to prevent patient, hospital and practitioner records being more freely accessible due to copy and forward restriction applied to patient or customer records.

European dialogues on DRM concerns

In Europe, there are several dialog activities, that are uncharacterized by its consensus-building intention:

  • Workshop on Digital Rights Management of the World Wide Web Consortium (W3C), January 2001. [4] (
  • Participative preparation of the European Committee for Standardization/Information Society Standardisation System (CEN/ISSS) DRM Report, 2003 (finished). [5] (
  • DRM Workshops of DG Information Society, European Commission (finished), and the work of the DRM working groups (finished), as well as the work of the High Level Group on DRM (ongoing). [6] (
  • Consultation process of the European Commission, DG Internal Market, on the Communication COM(2004)261 by the European Commission on "Management of Copyright and Related Rights" (closed). [7] (
  • The INDICARE project is an ongoing dialogue on consumer acceptability of DRM solutions in Europe. It is an open and neutral platform for exchange of facts and opinions, mainly based on articles by authors from science and practice. [8] (


  • Lawrence Lessig's Free Culture, published by Basic Books in 2004, is available for free download in PDF format ( The book is a legal and social history of copyright. Lessig is well known, in part, for arguing recent landmark cases on copyright law. A Professor of law at Stanford University, Lessig writes for an educated lay audience, including for non-lawyers. He is, for the most part, an opponent of DRM techologies.

See also

DRM implementations

Examples of existing "digital rights management" and "copy protection" systems:

Related concepts

External links

Lobbying organizations

es:Manejo de derechos digitales fi:Kyttestojen hallinta fr:Digital rights management it:Digital rights management nl:Digital Rights Management no:Digital rights management pl:Digital Rights Management zh:数字版权管理


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