Check boxes are still live after digital signature locks all other fields

[davidr21094623]

I have created a PDF fillable form with a digital signature. I want to ensure that once someone signs the document, it becomes uneditable.

When I tested the file out, the text fields are all locked after the form is signed and sent. However, when I open the file in Acrobat or Preview or any other PDF viewer, all of the check box answers are stil editable. How can I lock out ALL changes to the document after it is digitally signed?

[ls_rbls]

Hi, 

In edit mode, right-click on  the signtaure field that you want to apply the read-only settings for all content in your PDF document. 

It will open the signature field Action Properties; from the dialogue box that will open go to the "Signed" tab and then you can choose Mark As Read Only--->> All Fields  as the  action that will perform soon after that signature  is  applied.

For in-depth guidance on digital signatures see hre: https://www.adobe.com/devnet-docs/etk_deprecated/tools/DigSig/Acrobat_DigSig_WorkflowGuide.pdf

[davidr21094623]

Hello, ls_rbls, 

Thanks for your reply. 

Unfirtunately, I've already tried that. For some reason, even though I choose "All Fields" as "Mark as Read Only," the effect is only applied to the text fields within the form. All of the check boxes remain editable after the fact. 

[ls_rbls]

Well that is kind of strange; I've notice this behavior with other types of objects in an Acrobat  PDF document if radio buttons or checkboxes have any tye of mouseup actions or javascripts that are necessary  for other calculated fields to function.

Another issue that can be messing with your checkboxes is the tabbing order of the calculated fields which you can manually order or set to automatically use the document structure, then right-click on the checkbox fields and select use current defaults as new properties (but these are just trial and error ideas not an actual solution).

On my end, however, it is working fine. I tried reproduce your issue on my end but it works with the steps suggested above.

The real quick workaround that I'm almost sure it should is to delete the check boxes and save the document. Then with your document still opened, recreate new checkboxes with different names, save, exit, reopen.  And try the suggestion above again. It should work.

[davidr21094623]

I replaced all of the checkboxes with Radio buttons. While that appears to have helped when the signed document is opened once again in Acrobat — it is still editable when opened in Preview. In fact, I was even able to delete the entire completed signature box in Preview. 

Is this an inherent document security flaw with signed PDFs opened in Preview?

[ls_rbls]

I wouldn't jump just yet into that conclusion until you apply one or two more layers of security.

If the radio button method worked, and your PDF document is final, then apply a password to prevent further editing but saving  the document after that as Reader Extended.

FILE--->>>SAVE AS OTHER--->> READER EXTENDED PDF--->>>ENABLE MORE TOOLS

The reader extended by itself won't avoid users from editing if they open the document with Acrobat Pro, for example.

Using a password, will help a little better.

Do a test copy using that suggestion, try opening it in the Reader Mobile app and Acrobat Pro and you will notice that the user may be only restricted to fill, sign, comment and print, and save the signed document.

[ls_rbls]

I forgot to add, that my last suggestion really doesn't apply because you were referring to the actual filling of the form. But , nevertheless, that suggestion is to avoid users of Acrobat trying to mess with your PDF in edit mode.

The important detail here is to also delete that signature field and create a new one like you did with your checkboxes and then to radio button, and assigning a totally different name. Then don't forget to select in the signature field properties the signing action to mark everything as read only.

[marcu viorel]

Ok it very good thank you

[이경호]

kyoungho2233@gmail.com

[Test Screen Name]

Some apps will not respect "lock after signing". This is a flaw in the apps, NOT in the security. It is NOT a security feature, it is to protect the user against accidentally destroying the signature.

If an app like Preview ignores the signature lock and changes the file anyway, the signature will no longer be valid, and this will be detected. 

It is very important not to simply say "signed = unchangeable". Signatures must ALWAYS be validated as part of your processes.

[davidr21094623]

Interesting perspective on "security" vs. "protection".

What's also frustrating is that the document could be accidentally edited by anyone, e.g. a stray mouse click changing an answer from "Yes" to "No". In that case, how would it be remedied through the security process? By sending it back to the original signee?

[ls_rbls]

Can you sahre a dummy file or the page with the check boxes that are not taking the read only setting after a signature is applied?

I would like to see if this happens with every computer that this pdf file is used or if it is Acrobat settings.

[davidr21094623]

Sure. Are you asking me to email it to you?

[ls_rbls]

If you feel more confortable via private message yes, you cam email it, or , you can also share your file with Acrobat clicking on the share button; it will create a shared link in the document cloud that you can copy and paste here  in this thread (you can also use drop box, google drive, wet transfer, whicheever cloud service is more convenient for you).

[davidr21094623]

https://documentcloud.adobe.com/link/track?uri=urn%3Aaaid%3Ascds%3AUS%3A9e704d6a-6871-486d-ae95-12f6...

[Test Screen Name]

Well, let's see. The file is signed, and should be archived in a safe place, and backed up. If someone accidentally changes it later (or deliberately changes it of course), then validating the signature will instantly tell you this is not the document that they signed. So you restore it from the archive/backup. If there is none, then the only thing you can do is get it signed again, and try and fix your processes.