DRM is a class of access control technologies that are used with the intent to limit the use of digital content and devices after sale. DRM is not a specific technology, it is any technology that inhibits uses of digital content that are not desired or intended by the content provider. The use of DRM is controversial. The content providers claim DRM is necessary to fight copyright infringement and helps copyright holder maintain their creative commons, whereas the opposing argue that DRM serves only to inconvenience to legitimate customers and helps big business stifle innovation and competition. Also, if the DRM scheme changes or is discontinued then the works might become permanently inaccessible.
Some of the opponents such as Free Software Foundation say that the term “rights” in the abbreviation is misleading as DRM policies are mainly about imposing restrictions and not about giving rights.
DRM Technologies enable content providers to enforce their own policies on content, like restrictions on copying and viewing.
Common DRM Techniques:
Restrictive Licensing Agreements: The access to digital materials, copyright and public domain is controlled. Some restrictive licenses are imposed on consumers as a condition of entering in a website or when downloading software.
Encryption, Scrambling of expressive material, and embedding of a tag: This technology is designed to control access and reproduction of online information. This includes backup copies of personal use.
1. DRM and computer Games:
a) Limited install activations: Most computers from 2006 onwards limited the number of systems on which the game could be installed. This had a negative impact, wherein if a system was reformatted or if operating system was upgraded then the games re-installation would be treated as a new installation and subsequently adding up to the count limit of number of installations.
b) Persistent online authentication: “a need for an always-on connection”.
c) Software tampering: To prevent usage of pirated software. For example, in Croteam gaming while using a pirated software a foe I the game becomes invincible and constantly attack the player until the player is dead.
2. DRM and documents: Enterprise digital rights management is the application of DRM technology to the control of access of corporate documents such as PDF etc. Now it s commonly known as Information rights management(IRM) is intended to prevent the unauthorized use of proprietary documents.
3. DRM and e-books: Ebooks use DRM to limit copying, printing and sharing of e-books. There are four main ebook DRM schemes in common use, each for Amazon, Adobe, Apple and the Marlin Trust Management Organization.
a) Amazon’s DRM is applied to Amazon’s Mobipocket, KF8 and Topaz format.
b) Adobe’s Adept DRM is applied to ePubs and PDFs.
c) Apple’s Fairplay DRM is applied to ePubs.
d) Marlin DRM is maintained in an open industry group known as Marlin developer community.
4. DRM and film:
a) CSS Content Scrambling System: employed by DVD forum, uses an encryption algorithm to encrypt content on DVD.
b) Microsoft’s Windows Vista contains a DRM called Protected Media Path which contains the Protected Video Path which tries to stop DRM-restricted content from being played.
c) Advanced Access Control System is a DRM system for HD DVD.
5. DRM and music
a) Audio CDs: Discs with digital rights management schemes are not legitimately standards-compliant Compact Discs (CDs) but are rather CD-ROM media. Therefore they all lack the CD logotype found on discs which follow the standard . Therefore these CDs could not be played on all CD players.
b) Internet music: Many online music stores employ DRM to restrict usage of music purchased and downloaded online.
6. DRM and television
a) Cable card standard provided by cable television providers in US restricts contents to only the services which the customer has subscribed.
b) Broadcast Flag developed by Fox in 2001 required that all HDTVs obey a stream specification determining whether or not a stream can be recorded. This was later adopted by DVB.