Digital Rights management

Digital Rights Management (generally abbreviated to DRM) is any of several technologies used by publishers to control access to digital data (such as software, music, movies) and hardware, handling usage restrictions associated with a specific instance of a digital work. The term is often confused with copy protection and technical protection measures (TPM). These two terms refer to technologies that control or restrict the use and access of digital media 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. The position put forth is that copyright holders are attempting to restrict use of copyrighted material in ways already granted by statutory or common law applying to copyright. Others, such as the Electronic Frontier Foundation consider some DRM schemes to be anti-competitive, citing the iTunes Music Store as an example.

Enterprise Digital Rights Management (E-DRM or ERM) refers to the use of DRM technology to control access to corporate documents (Word, PDF, TIFF, AutoCAD files, etc), rather than consumer playable media. The technology usually requires a Policy Server to authenticate users' rights to access certain files. EDRM vendors include Microsoft, Adobe Systems, EMC Corporation/Authentica and several smaller companies. There are open source implementations as well. EDRM is generally intended to apply to trade secrets, which are much different than copyrighted material (though there is sometimes an overlap with material being both copyrighted and a trade secret -- eg, software source code), and for whom the primary issue is industrial or corporate espionage or inadvertent release. In most jurisdictions, there is no notion of fair use of trade secrets as there is for copyrighted material. Trade secrecy confidentiality measures are less controversial than DRM applied to copyrighted material, which is commercially sold in many copies.

Overview

DRM vendors and publishers coined the term digital rights management to refer to the types of technical measures discussed here, applying it only to digital media (and analog media that has been released in digital form). There is a long history of objection on the part of copyright holders (often music distributors or broadcasting companies) to copying technology of any kind. Examples have included player piano rolls (early in the 20th century), audio tape recording (after WWII), video tape recording (eg, in the famous Betamax case in the US), etc. Digital copying raised concerns to a higher pitch. While analog media loses quality with each copy generation, and often even during normal use, digital media files may be copied an unlimited number of times without degradation in the quality of subsequent copies. Digital Audio Tape, thought by many observers of the time to be a probable replacement / improvement for the audio cassette, was a market failure in part due to opposition on grounds of potential piracy. The advent of personal computers, combined with the Internet and popular file sharing tools, have made unauthorized sharing of digital files (often referred to as digital piracy) possible and profitable.

Although technical controls on the reproduction and use of software have been intermittently common since the 1980s, the term DRM has come to primarily mean the use of similar measures to control artistic works or content. Beyond the existing restrictions imposed by copyright law, most DRM schemes are able to enforce additional restrictions at the discretion of the content's publisher, which may or may not be the same entity as the copyright holder.

DRM may be enforced by numerous technologies, such as special modifications to digital media player software. Since such implementations can be reverse engineered, they are not 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) wherein usage restrictions are enforced by software buried in hardware, working with software provisions in operating systems, media playing software, or both. However, some implementations of this type of DRM are vulnerable to an additional class of attacks, due to a requirement to run on tamper-resistant hardware. There has been pressure (largely successful) for legislation and regulation creating new offenses (ie, controlling or prohibiting examination of DRM schemes, or possession of any tools (eg, 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 (films and recording), it has found use in other media as well. Many online music stores, such as Apple’s iTunes Music 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 system, and its equivalents.

Content Scrambling System

An early example of a DRM system is the Content Scrambling System (CSS) employed by the DVD Forum on movie DVDs since circa 1996. The scheme used a simple encryption algorithm, and required device manufacturers to sign a license agreement restricting the inclusion of certain features in their players, such as a digital output which could be used to extract a high-quality digital copy of the movie. Thus, the only consumer hardware capable of decoding DVD movies was controlled by the DVD Forum, restricting the unauthorized use of DVD media until the release of DeCSS by Jon Lech Johansen in 1999. An unsuccessful variant of this scheme is the now-defunct DIVX format.