Plugin for password protected page

Hi, i want to make a quiz page in my wordpress site, but the quiz page is password protected. And if anyone want to participate in this quiz, they should insert their email in the some kind of form and then an auto generated password for the quiz page will be sent to their email. So they can participate the quiz and i can have their email for promotion purpose in the future.

And my question, is there any plugin that can make a password protected page and can be unlocked by various password, and a plugin that can sent the registered user a random passoword for the page and their email is saved in a database?