In its early incarnations, digital rights management (DRM) simply meant ensuring that file content could be viewed only by authorised users. Current DRM systems have expanded their scope to define pricing and usage policies as well as to distribute content across a variety of devices. However, standards to support DRM are still emerging, which has led to some incompatibilities between systems. This is delaying widespread adoption of DRM technology.
The legal difficulties of Napster, a file swapping service for music on the Web, showed that the music industry needs a way of managing digital rights online. Other emerging technologies such as electronic books have a similar requirement. Intellectual property management is the core focus of DRM, together with the need for tools to support commercial distribution of content. A number of systems are now emerging to support the full process of distributing and managing digital materials. A key requirement is to clearly define how access to material will be granted, and at what cost.
Sales options
DRM processes can be loosely grouped into three areas: encryption and capture of content; distribution; and asset management. The first of these is the best-established area of DRM, with file formats such as Adobe's PDF already supporting encryption for e-books. Similarly, emerging formats such as the new MPEG 4 standard provide improved features for content encryption.
Encryption should protect files from access by unauthorised users, but many current encryption systems have weaknesses. For example, Adobe's eBook files can be decrypted by ElcomSoft's Advanced eBook Processor.
There is also a need to define how copyright material can be used. Languages for this purpose are still emerging. One of the most significant is Extensible Media Commerce Language (XMCL), which is supported by IBM, Real, Adobe and DRM specialist InterTrust, among others. XMCL provides an open XML-based standard for rights definition, allowing interoperable systems to be created.
Distribution processes should define how digital content is purchased and used. This capability was weak in early DRM systems, and often imposed onerous restrictions on users. For example, systems frequently associated usage rights with a machine, rather than an individual. This meant content could be used only on the machine to which it had first been downloaded. Newer products, such as SealedMedia, have introduced roaming access to documents, enabling a user to access purchased content on any suitable device. This is particularly appropriate to media such as e-books, which may be accessed through a PC as well as a mobile device. To maintain digital rights, SealedMedia allows only a single copy of a file to be opened at any one time. DRM systems also need to support a variety of purchase options, including outright purchasing, subscriptions, pay-per-view, or a finite number of accesses to content.
A model of licensing established by Interact is now widely supported by other DRM systems, including Microsoft's Windows Media Rights Manager. This model is called superdistribution and enables a customer to distribute a file to other users, but each recipient must then acquire their own licence before they can access the content.
Once a customer has bought a file, the content is viewed through a compatible viewer or player. This must be capable of interpreting both the content data and rights information stored with the file. For music formats such as MP3, a player such as Real Audio Basic would be used; for e-books stored in PDF format, Adobe Acrobat Reader is a common reader. A number of systems such as SealedMedia also use proprietary viewers. In the case of SealedMedia, the viewer can read a variety of formats, including PDF, MP3 and Real Audio from within a single application.
However, incompatibility of viewers and poor interoperability between file types is still a significant problem for digital distribution.
End-users often require a range of viewers to access the various types of content available online. Viewers or players capable of working with digital devices other than PCs are developing apace. InterTrust has been particularly active in such developments, forming relationships with mobile phone vendors, for example, to ensure that future handset chips are DRM-compatible.
Once content has been delivered to a user, asset management systems enforce the terms of access. This may include monitoring pay-per-view arrangements, or ensuring that only appropriate users gain access to files or documents. This may be particularly important in corporate settings. A DRM system can ensure that files are only accessed by authorised individuals, and that permissions are immediately revoked if an employee leaves the company. DRM systems can also provide file-level access control, offering more granular data access management than traditional network-level security.
Information collected through an asset management system can be used for other commercial initiatives. For example, information on how customers pay for access can be used to develop subsequent goods or marketing campaigns.
Music and text publishers are currently the main customers for DRM, but similar technologies are used for other purposes  for example, to protect and control information in the recruitment and education industries.
Collating college course materials is one application of DRM in an academic setting. Individual chapters from e-books can be added alongside original tutor notes to create a package of course materials. Students can then be granted access to the materials for the duration of their course, or may be permitted to print a chapter for personal use, for example.
Compatibility issues
DRM systems will allow new sales models for goods such as e-books. These models are already emerging in areas such as scientific publishing, where customers can purchase a single chapter of a book rather than a full text, for example. Robust DRM technologies will also facilitate online publication of reports such as time-critical research.
The ability to combine different types of content within a single offering can also add value to offerings.
It is likely to be another 12 to 18 months before DRM systems are widely used by corporates, and common, widely adopted standards will be required.
Companies such as RightsCom currently provide consultancy to companies that want to sell digital content, and it is taking part in many of the current standards initiatives, including MPEG-21 Â a multimedia framework for end-to-end DRM for content such as audio files and videos. The Open eBook Forum is another standards initiative, and is designed to develop a consistent framework for protecting e-books.
A lack of interoperability between media players and viewers is currently a problem for users and content providers. Microsoft's Windows Media Rights Manager is one of the proprietory formats and may be more appealing than some of its rivals because it is widely used, thanks to the ubiquity of Windows MediaPlayer. However, in the longer term firms will want a system that can support digital content across a wide range of devices and formats. In the case of Windows Media Rights Manager, file type support is limited to Microsoft's own file formats.
Buying a full DRM system can be very expensive for a company. However, application service providers (ASPs) hosting software online can offer an alternative. For example, ASP DotEncrypt uses SealedMedia's architecture to offer a bespoke DRM application online. Prices begin at £50 a year for publication of 600 documents, plus charges based on usage  perhaps 15 percent of each transaction. This approach may be particularly attractive for smaller companies that do not have the money or in-house expertise to set up their own DRM systems.
DRM has evolved from simply being a method of encrypting files, to being a method of supporting the complete process of preparing, distributing and managing access to content online. The technology can protect copyright and encourage more flexibility in selling digital products online. Corporates can also use DRM to improve file access management. However, for such applications to become widely used, more standardisation of DRM systems, players and viewers will be necessary.
