I'm using OSX (10.5.8) and CS5 (may soon upgrade to 5.5). My client has an aviation manual that I will be converting from InDesign to an ebook (.epub, fixed-layout, via CircularFlo software) so he can sell either through iBookstore or his own website. But he wants to protect the manual with a key so that only
designated buyers---i.e. trained students----have access to it, and so it can't be easily shared. (ideally, buyers would only have to use the key once, not every time.) At what stage does such encryption happen (layout? conversion? distribution?). This must be common practice---for military, medical, scientific materials and so on----where can I learn more about how to do it? Thanks.
The most common kinds of encryption occur at the time of publishing. Adobe has such a system (but it requires big bucks). Apple can apply encryption to books sold on the iBookstore.
It might be easiest to create a protected area of your website which requires a password.
Try asking in the MobileRead forums where there are probably more people with such experience.