to read drm epub in Kindle, or read a public library ebook in ipad, you can do that until you strip drm from epub ebook, this is tutorial to do that.
1. download ePub drm removal from ebook-converter.com, this tools has an easy-to-use interface to help new comers get up to speed.
2. Run ePub drm removal, select your epub file which you want to decrypt, click “Remove” button, a new epub file created withou drm protect.
3. Drag drop new epub to itune if you want to read in iPad.
4. Convert epub to Mobi format if you want to read it in Kindle reader. another tutorial of mobi conversion click here
EPUB is a free and open e-book standard by the International Digital Publishing Forum (IDPF). Files have the extension .epub.
EPUB is designed for reflowable content, meaning that the text display can be optimized for the particular display device used by the reader of the EPUB-formatted book. The format is meant to function as a single format that publishers and conversion houses can use in-house, as well as for distribution and sale.
An EPUB file can optionally contain DRM as an additional layer, but it is not required by the specifications. In addition, the specification does not name any particular DRM system to use, so publishers can choose a DRM scheme to their liking. However, future versions of EPUB (specifically OCF) may specify a format for DRM.