Digital rights management (DRM) is a generic term that refers to access control technologies used by hardware manufacturers, publishers and copyright holders to limit usage of digital media or devices. It can also refer to restrictions associated with specific instances of digital works or devices. DRM overlaps with software copy protection to some extent, however the term "DRM" is usually applied to creative media (music, films, etc.) whereas the term "copy protection" tends to refer to copy protection mechanisms in computer software.

Digital rights management has been and is being used by content provider companies such as Sony, Apple Inc., Microsoft and the BBC.

Digital rights management technologies attempt to control use of digital media by preventing access, copying or conversion to other formats by end users. Long before the arrival of digital or even electronic media, copyright holders, content producers, or other financially or artistically interested parties had business and legal objections to copying technologies. Examples include: player piano rolls early in the 20th century, audio tape recording, and video tape recording (e.g. the "Betamax case" in the U.S.). Copying technology thus exemplifies a disruptive technology.

Although technical controls on the reproduction and use of software have been intermittently used since the 1970s, the term 'DRM' has come to primarily mean the use of these measures to control artistic or literary content. DRM technologies have enabled publishers to enforce access policies that not only disallow copyright infringements, but also prevent lawful fair use of copyrighted works, or even implement use constraints on non-copyrighted works that they distribute; examples include the placement of DRM on certain public-domain or open-licensed e-books, or DRM included in consumer electronic devices that time-shift (and apply DRM to) both copyrighted and non-copyrighted works.

While DRM is most commonly used by the entertainment industry (e.g. film and recording), it has found use in other situations as well. Many online music stores, such as Apple's iTunes Store, as well as certain e-book publishers, have imposed DRM on their customers. In recent years, a number of television producers have imposed DRM mandates on consumer electronic devices, to control access to the freely-broadcast content of their shows, in connection with the popularity of time-shifting digital video recorder systems such as TiVo.

Digital rights management systems have received some international legal backing by implementation of the 1996 WIPO Copyright Treaty (WCT). Article 11 of the Treaty requires nations party to the treaties to enact laws against DRM circumvention.

The WCT has been implemented in most member states of the World Intellectual Property Organization. The American implementation is the Digital Millennium Copyright Act (DMCA), while in Europe the treaty has been implemented by the 2001 European directive on copyright, which requires member states of the European Union to implement legal protections for technological prevention measures. In 2006, the lower house of the French parliament adopted such legislation as part of the controversial DADVSI law, but added that protected DRM techniques should be made interoperable, a move which caused widespread controversy in the United States.

The stated intent of DRM is to provide technical means to assure that the copyright holders (originally artists, but commonly assigned to publishers, software developers, etc.) can maintain control of their content by restricting use of digital copies. This becomes controversial because DRM imposed limitations on the use of legitimately acquired digital media do not necessarily match the fair use (fair dealing in some places) rights granted by law to owners of copies. This gives rise to concerns that DRM schemes enormously complicate, and may prevent, effective archive management and historical research as well. Others argue that DRM is ineffective at preventing illegal copies because no DRM technology is (or could possibly be) fool proof. Once one version is compromised (or simply copied from a medium without DRM) it will become widely available, e.g. on the Internet or via large-scale commercial piracy. Thus all DRM to date is claimed to be fundamentally technically flawed as a method of protecting legal copyright control. If so, its effect is essentially to ensure vendor lock-in and, likely, anti-competitive practices afterwards. DRM opponents usually base their opposition on one or more of these concerns.

All forms of DRM for audio and visual material (excluding interactive materials, like videogames) are subject to the analog hole, namely that in order for a viewer to play the material, the digital signal must be turned into an analog signal containing light and/or sound for the viewer, and so available to be copied as no DRM is capable of controlling content in this form. In other words, a user could playback a purchased audio file while using a separate program to record the sound back into the computer into a non-DRM protected file format.

All DRM to date, and probably all future ones can therefore be bypassed by recording this signal and digitally storing and distributing it in a non DRM limited form. However the conversion from digital to analog and back is likely to force a loss of quality, particularly when using lossy digital formats.

Conclusions

Of late, digital rights management has become a topic of debate and controversy in the IT industry. Advocates argue it is necessary for copyright holders to prevent unauthorized duplication of their work to ensure continued revenue streams. Opponents, such as the Free Software Foundation, maintain that the use of the word "rights" is misleading and suggest that people instead use the term Digital Restrictions Management (DRM). Their position is essentially that copyright holders are attempting to restrict use of copyrighted material in ways not covered by existing laws. The Electronic Frontier Foundation, and other opponents, also considers DRM systems to be anti-competitive practices.

In practice, all widely-used DRM systems have been defeated or circumvented when deployed to enough customers. Restricting copying of audio and visual material is especially difficult due to the existence of the analog hole, and there are even suggestions that effective DRM is logically impossible for this reason.