Background info on DRM

[Robert La Ferla]

Excerpt from http://www.gromkov.com/faq/faq2004-0040.html:

DRM is a set of technologies content owners can use to protect their 
copyrights and stay in closer contact with their customers. In most 
instances, DRM is a system that encrypts digital media content and 
limits access to only those people who have acquired a proper license to 
play the content. That is, DRM is a technology that enables the secure 
distribution, promotion, and sale of digital media content on the Internet.

When a user plays protected content for which he or she does not have a 
license, the player launches the license acquisition URL stored in the 
content header. The player sends a license request, which includes the 
entire content header and some system information, to the license 
provider's Web page. The key ID is extracted and then used with the 
license key seed to regenerate the encryption key, which is then 
included in the license.

The license provider then determines which rights to grant according to 
a process that has been established with the content owner. For example, 
the content owner could use attributes to communicate the rights to 
issue )B— a string could indicate the rights. Or, the content owner's ID 
could be included as an attribute, which the license provider could look 
up in a database that contains the rights to grant for each content 
owner account. Finally, a license is issued and the user can play the 
content.