title: How to do DRM for ePub files?
body: <p>I am going to create a mobile book store for a very specific group of people. Since ePub is just compressed HTML, it's not secure enough. Anyone can access it if I extract the files to SD card. I don't want users copy the E-books around because I sell them for money.</p>
  
  <p>I can parse the file and save it to a database. But I wondered if there is standard way for managing ePub DRM?</p>
  
  <p>Thanks,</p>