One main problem is that you have to make passwords recoverable. In real world message like "warring! we can't restore your key!" just doesn't work at all. Peop

One main problem is that you have to make passwords recoverable. In real world message like "warring! we can't restore your key!" just doesn't work at all. People ignore it and still want you to recover their keys. Also forcing people to have password is also very vulnerable.