Digital Rights Management (DRM)

Digital Rights Management (DRM) is an umbrella term referring to technologies used by publishers or copyright owners to control access to or usage of digital data or hardware, and to restrictions associated with a specific instance of a digital work or device. The term is often confused with copy protection and technical protection measures, which refer to technologies that control or restrict the use and access of digital content on electronic devices with such technologies installed, acting as components of a DRM design.

Digital Rights Management is a controversial topic. Advocates argue DRM is necessary for copyright holders to prevent unauthorized duplication of their work to ensure continued revenue streams. Some critics of the technology, including the Free Software Foundation, suggest that the use of the word "Rights" is misleading and suggest that people instead use the term Digital Restrictions Management. Their position is essentially that copyright holders are attempting to restrict use of copyrighted material in ways not included in the statutory, common law, or Constitutional grant of exclusive commercial use to them. Others, such as the Electronic Frontier Foundation consider some DRM schemes to also be anti-competitive practices, citing the iTunes Store as an example.

Introduction
Digital rights management technologies attempt to control or prevent access to or copying of digital media, which can be copied with very little cost or effort. Copyright holders, content producers, or other financially or artistically interested parties have historically objected to copying technologies, before digital media. Examples have included player piano rolls early in the 20th century, audio tape recording, and video tape recording (e.g. in the Betamax case in the US). The advent of digital media increased concerns. While analog media inevitably loses quality with each copy generation, and in some cases even during normal use, digital media files may be copied an unlimited number of times with no degradation in the quality of subsequent copies. Digital Audio Tape, thought by many observers of the time to be a probable replacement for the audio cassette, was a market failure in part due to opposition to it on grounds of unauthorized copying potential[citation needed]. The advent of personal computers, the ease of ripping media files from a CD or from radio broadcast, combined with the internet and popular file sharing tools, has made unauthorized dissemination of copies of digital files (often referred to as digital piracy) much easier. This has concerned some digital content publishers, leading some to pursue DRM technologies to try to prevent those actions.

Although technical controls on the reproduction and use of software have been intermittently common since the 1970s, the term DRM has come to primarily mean the use of these measures to control copyrightable artistic content. Some DRM technologies enable content publishers to enforce access policies that go beyond preventing copyright violations, and also prevent legal fair use.

DRM schemes are built on numerous technologies, such as modifications to digital media player software to include cryptographic controls on access. Since such implementations can in principle be reverse engineered, and in practice frequently are, they cannot be fully effective as an inherent part of the design. This fact has resulted in a general move toward Mandatory Access Control systems (as opposed to Discretionary access control) in which use restrictions are enforced by firmware (ie, software permanently embedded in hardware), or especially in recent releases of some operating systems, in the heart of the operating system. These software/firmware/embedded hardware controls interact with operating systems, media player software, or both to achieve their DRM goals. However, some implementations of this DRM type are vulnerable to an additional class of attacks, due to the requirement for running on tamper-resistant hardware. There has also been pressure (successful in some places) for legislation and regulation creating new offenses (ie, controlling or prohibiting examination of DRM schemes, or possession of any tools (e.g., software) which might interfere with the operation of a DRM scheme.) An example is the DMCA.

While digital rights management is most commonly used by the entertainment industry (e.g., films and recording), it has found use in other media as well. Many online music stores, such as Apple's iTunes Store, as well as certain e-books producers, have adopted various DRM schemes in recent times. In recent years, a number of television producers have begun demanding implementation of DRM measures to control access to the content of their shows in connection with the popular TiVo time-shifting recorder system, and its equivalents.

http://en.wikipedia.org/wiki/Digital_Rights_Management