In essence, when you purchase a copy of the book, it has the full and complete book. When you share the book with anyone else, the encryption will randomly change the text in a book. It will do this every time a new copy of the book is distributed. This will result in thousands of different versions of the book, with text being augmented on a wide scale. Publishers have tools that allow them to grab the pirated copy and trace it back to the original purchaser. This is designed to stop piracy and make people accountable and ditching without the bulky aspect of 95% of today’s DRM.
Read the full article @ goodereader.com.