Flatten PDF after Signature

[Ranjeet5C86]

My PDF has textfields, checkfields and signature fields. Ideally the Signer fills out the form and then signs all the signatures.

But it is technically possible to change a field after a signature has been entered.

How can I design the PDF in such a way, that makes it impossible for the Signer to change a field after a signature? I mean a kind of sealing of the PDF.

[BarlaeDC]

Hi,

It might be technically be changeable, but the signature would be marked as invalid, meaning that you can see that the doc has been changed since it was signed.

When you sign you can select to lock document after signing

does this not solve the problem?

[Ranjeet5C86]

It does not, because the Document is signed by a costumer and that person may not know how to do it or may not want to do it.

Is there no automatic solution?

I remember a popup saying "Invalid signature". May I ask in which PDFDictionary entry stores such an information?

[try67]

Go to the Properties of the signature field and under the Signed tab select the option to set all fields as Read-Only:

[Ranjeet5C86]

That is an interesting concept. May I ask how to archive that in PDFBox? The PDF is generated in C++, than goes through a webservice and there I wanted to modify the pdf. I would love to execute a script once it is signed.

[Ranjeet5C86]

Unfortunatly I did not find that Property. Where exactly do I find it?

[try67]

Are you using Acrobat, or are you doing it using a stand-alone application?

[Ranjeet5C86]

I try to modify the PDF inside PDFBox. The User ideally would not even recognize it, but would sign the Document inside Adobe Acrobat Reader 5 or younger.

[try67]

I recommend asking over at the PDFBox mailing list: users [at] pdfbox.apache.org