Readium LCP employs military-grade encryption to protect e-book contents, and to decrypt the contents a passphrase is needed. This passphrase is determined during download link (otherwise known as a transaction) creation, either through our APIs or web UIs.
Once your end-user has their download link and uses it with an LCP compliant reader application, they will then be shown a passphrase hint (which is again determined during transaction creation) so they can complete fulfillment.
Below is the default instructions page is shown to end-users by EditionGuard during fulfillment. You may wish to keep using this page or use a customized version of this page hosted on your own web servers.