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Participant
January 9, 2022
Question

Unable to apply a Document time stamp to a Certified PDF

  • January 9, 2022
  • 1 reply
  • 3206 views

Applying a Document time stamp works on digitally signed documents, even if the document has been locked after applying a digital signature. This is expected behavior in order to comply with the requirements of PAdES-B-LTA.

However, if a document was first certified with a digital signature, I won't be able to apply a Document time stamp to it afterwards. Why is that? Am I missing something?

Applying a Document time stamp on such documents while retaining compliance, in my case with eIDAS, is still achievable with other tools based on the DSS framework, however not through Adobe Reader/Acrobat.

 

Is there a way to achieve this functionality solely by using Adobe PDF solutions?

This topic has been closed for replies.

1 reply

Amal.
Community Manager
Community Manager
January 10, 2022

Hi Ivan,

 

Hope you are doing well and sorry to hear that.

 

It is the designed behavior of Adobe Acrobat/Reader DC application. Once the PDF file is signed and the signature process is completed it gets locked for further editing. For more information about editing a signed PDF please check  the help page https://helpx.adobe.com/acrobat/kb/edit-signed-PDF.html

 

Regards

Amal

Participant
January 11, 2022

Hi Amal, and thank you for answering my question. I understand now that it is not possible to apply a document time stamp to a certified/signature-locked PDF. That is unfortunate, though, because while I understand that locking the document is meant to disable/discourage any changes being made to it, I don't really see how applying a document time stamp would constitute a change to the document. In other words, I don't think that applying a document time stamp would result in invalidating the applied signature(s), but I may be wrong there...

Amal.
Community Manager
Community Manager
April 11, 2022

We advise our users to never use "Lock document after signing".


Hi there

 

Occasionally, you or the signer may choose to lock the document after signing. In this case, the document becomes read-only and no further changes are allowed; even a signature can’t be added in the document. The Lock document after signing option is useful if you’re the last signer or the only one signer.  as described in the help page shared earlier.

 

Regards

Amal