I am self-publishing a secondary textbook. In order for my local state to allow schools to purchase the physical textbook and use it in their classrooms, I'm legally required to make an on-line version available to purchasers (i.e. any students in districts who purchased the book). This should be a simple means, not requiring any fancy software, just a web browser.
Do any of the major self-publishing services (such as B&N Press, Lulu, or Amazon Self-Publishing) have a means to generate a password, that I could mail out in mass, so those students can read an e-version free, but the general public is locked out?