Similarly in the field of music and movies, some publishers and retailers use systems digital rights management (DRM) to try to protect the works. Most of these systems are relatively inefficient and penalize its use in the reader of the book.
|Adept||Adobe||ePub, pdf, ascm||Majorité, Kobo, B&N, Sony, Google||DRM standard often used. It requires an account on the Abobe site and limit the readability of a book to six devices.|
|Kepub (Adept)||Kobo (Adobe)||kepub||Kobo||This is with a few more EPUB data. The files can be downloaded in Adobe DRM + ePub standard format|
|Topaz||Amazon||azw, tpz||Amazon||Amazon new format, based on his previous Mobipocket|
|Mobipocket||Amazon||mobi||Amazon (ancien)||Format created by Mobipocket (acquired by Amazon). Works with a system of PID (unique key hardware).|
|Ignoble (basé sur adept)||B&N (Adobe)||B&N||Extension of Adobe’s ADEPT DRM which also used name and credit card number as a key (to discourage sharing)|
|eReader||B&N||pdb, pml||B&N (ancien), Palm||Old B & N format, which also uses the name and credit card number as a key to social sharing brake|
|FairPlay||Apple||Apple||Used on iBooks and files are readable only by Apple devices, no research to date fault|
Some digital books do not contain digital rights management system, but watermarks, usually the name of the buyer and email address.
Numerous free works of law (as in the public domain) are available for free download on many websites, including for example the Project Gutenberg or the Open Library, Manybooks, or feedbooks / publicdomain Public Domain Books, etc.