Version 7.1.0 of the tools is now available. Please update to the latest version if you are having issues. To leave a comment, see this post: DRM Removal Tools for eBooks.
DeDRM_tools_7.1.0.zip can be downloaded from
This release is for calibre 5.x. It includes the DeDRM and Obok plugins, versions 7.1.0.
For calibre 4.23, you must use the 6.8.1 DeDRM plugin, but the included Obok 7.1.0 plugin should work with calibre 4.2.3.
There may well still be problems with the DeDRM plugin. If you find a book that can be decrypted with calibre 4.23 and DeDRM 6.8.1, but that does not decrypt with DeDRM 7.1.0, please send me the original encrypted book, and your key exported from the DeDRM 6.8.1 preferences. I will try to reproduce the problem and fix the bug. Please send books and keys to firstname.lastname@example.org
Please DO NOT send me anything unless you can get it to decrypt successfully with calibre 4.23 and DeDRM 6.8.1