May be, it's a silly question, but even after studying the documentation I don't know how to solve that:
- design a form
- distribute the form via email or download
- users should be able to fill in the form but not to change the layout and so on, even if they have installed designer or acrobat or some other pdf tool AND users shouldn't be forced to enter a password to fill in the form!
Under Form Properties/PDF Security there is a "Require a password to open the document" option. If you check this then when you save the doc you can enter a password that is required to open the doc for edit as well as filling.
Conversely if you make sure the above option is unchecked, then set permissions on the doc then the "Changes Allowed" dropdown becomes active. You can choose the "Fill in the Form and Sign" option and that will allow a user to interact with the doc without entering a password but if they try to open the doc in Designer a password would be required. Note that you must save your form as a PDF for this to work. When you save a password dialog will be presented to you so that you can enter your password.
Many thanks for your answer. Indeed, this is one possible solution, but I guess it doesn't meet the security requirements of my customer. You get a warning if you apply the password, that this password-security may be circumvanted.
Is there another possibility, e.g. signing or certifying the form, so that it can not be changed execpt fill in and signing?