Protect PDF after Certified Signature

Is there a way to prevent a PDF document's content from being altered after it is signed with a digital signature pad?

Steps I have successfully taken so far:

1. Used DC Pro's "Prepare Form" tool to add 3 input fields to my document: Sign, Date, and ID#.

2. Used document level JavaScript to populate the Date field with System Date, and ID# field with the document's file name (excluding the file extension).

3. Used DC Pro's "Certificates" tool to define a signature field, with Topaz Sig Pad as the default input.

4. Closed the PDF document and reopened it with Reader DC as the default program. The Date and ID# fields were automatically populated as desired and I signed the Signature field with the Topaz pen.

5. Closed the document.

The problem I'm having now is that even through Reader DC I can subsequently alter the Date and ID# fields and save those changes in the same document.

I see that Preferences in DC Pro contain encryption and password options (which I can't use for my purposes) but I cannot see any security options to prevent document changes after a certificate signature is added - is there a way to make that possible?

Alan Grant

2 Answers

Voted Best Answer

I don't have access to a Topaz pad, so this may not work correctly, in which case you should get in touch with Topaz' support.

When you create a signature field, you can define what will happen with form fields:

Signature Properties

When you bring up the properties for the signature field, and go to the "Signed" tab, you can define what should happened to form fields. In the example above, I've selected to make all of them read-only. You can also leave some open for further modifications (e.g. if you have a second signature field, that needs to be available for modifications, otherwise you can no longer add that 2nd signature).

Karl Heinz Kremer
PDF Acrobatics Without a Net
PDF Software Development, Training and More...

By Karl Heinz Kremer   

Correction - Step "1" should just reference 2 fields - Date and ID#.

Alan Grant   

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