If you’re a Dropbox Pro or Dropbox for Business user, you can set a password for any shared link that you create. This helps to ensure that only collaborators with the password can access your shared content.
Keep in mind that members of a shared folder can create multiple unique shared links to its contents. That means you and another shared folder member can create links with different passwords to the same file or sub-folder.
Follow these steps to add, modify, or remove a password for a shared link:

Once you’ve saved your settings, you can copy and paste the link to an email or send it directly to your collaborators through Dropbox.
If someone tries to view a shared link with a password, they’ll see this page:

Once they enter the password, they’ll see the normal shared link page.
You can reset the password for any link you've shared in the same way that you set the password. If you’ve forgotten the password, you’ll need to create a new password, or you can always disable the link. For security reasons, we'll never display your existing passwords.
Admins don’t have the ability to enforce password policies for the team's shared links, but admins can restrict all shared links to be team-only from the Admin Console. If links are restricted to team-only and a shared link has a password set, only team members with the password can access the link.
If someone types an incorrect password for a link, they’ll be notified with an error message.
