This document describes three types of copyright protection technologies in use in the publishing industry:
- DRM free protection, i.e. technologies which does not rely on content encryption but rather use content fingerprinting or watermarking, adequate for use cases where user convenience is the top priority;
- user key-based DRM protection, adequate where user constraints are limited;
- device key-based DRM protection, adequate where the transfer of publications from one device to another is severely constrained.