Yes, there are several options to make sure your form is protected from spam.
You can protect your forms against spam by restricting submissions to one submission per IP address, as long as your users won’t be using the form multiple times. You can also set up conditional logic for another layer of protection.
We encourage our users to add a CAPTCHA to their forms, which is very effective if spam is coming from bots. This can work in tandem with password protection, though keep in mind that this would require you to provide the password to all of your users.