DRM

Short for digital rights management, a system for protecting the copyrights of data circulated via the Internet or other digital media by enabling secure distribution and/or disabling illegal distribution of the data. Typically, a DRM system protects intellectual property by either encrypting the data so that it can only be accessed by authorized users or marking the content with a digital watermarkor similar method so that the content can not be freely distributed.

Also see SSL: Your Key to E-commerce Security in Webopedia's "Did You Know...?" section.