1. Field of the Invention
This invention generally relates to network-based delivery of digital content and more specifically enforcing digital rights in such content.
2. Description of the Related Art
Digital rights management (“DRM”) technologies allow content owners to restrict usage of content by end users. DRM systems can be used to protect various types of content in various types of computing environments. The content can include, for example, word processor documents, images, e-books, music and software applications.
Increasingly, DRM systems are required to operate in heterogeneous computing environments. For example, the computing environment can include laptop computers, mobile phones, audio players, video players and/or e-book readers. These devices are produced by a variety of different manufacturers and have different capabilities. A laptop computer, for example, might allow any type of content to be e-mailed or otherwise transferred to other computers, while a mobile phone might play audio files but not allow these files to be transferred to another device.
DRM systems apply rights policies to content. When content is transferred to a device the rights policy defines restrictions that limit the ability of other devices to use the content. For example, the rights policy can specify that a word processor document cannot be edited by end users. However, in many instances the DRM system will not provide coverage for all the devices operating in the computing environment. For example, the DRM system may not be able to enforce a read-only policy on a certain device. Thus, in these instances the end-user device may have unlimited use of content that was intended to be restricted, or be unable to receive the content provided by the DRM system.