But you still need to store the login and version number for each domain in a database. And provide the secret key. At this point you might as well store the encrypted password along with the rest.
Login and secret key are from memory (especially login for important accounts). Version number is typically pretty small and thus guessable. Like I said, it worked perfectly for critical stuff when my laptop died recently. There is no database. I used the important accounts from memory to bootstrap my way into github where the full config is saved.