Removing Signatures from PDFs in Acrobat Pro 9

***EDIT 1/2/2013*** This article describes the process of exporting your PDF as a PostScript file and redistilling it to remove digital signatures. What I failed to make explicit in the original article is that this procedure WILL REMOVE ALL INTERACTIVE FEATURES, including form fields, buttons, hyperlinks, etc., as they are not supported in PostScript. In the scenario described in my article, this was not an issue, and in the time since I wrote the article I’ve had a number of readers inform me they have found the information helpful for them as well. However, a recent comment made me realize my omission.

Again, if you have interactive elements such as form fields, buttons, hyperlinks, etc. in your PDF that you need to preserve, DO NOT export to a PostScript file as they will be lost. And obviously, when redistilling, do not overwrite your original PDF file.
***

Today I ran across a problem as I was editing metadata in a set of PDFs that are to be included on an indexed CD publication. Several of the PDFs had signatures, and therefore disallowed any changes. According to the official Acrobat help, “You cannot remove a signature unless you are the one who placed it and you have the digital ID for signing it installed.” While the signatures might have been important in their original workflow, they’re irrelevant for this project. I don’t want to have to go back to my client and ask for new unsigned PDFs just so I can make minor changes to the metadata. A Google search on the Internet for removing signatures via some other means yielded no results except an old script hack from several versions ago, which may or may not work in 9; I didn’t want to try it.

So I started experimenting, and after a few minutes I found a simple solution:

  1. Export the PDF as a PostScript file (File: Export: PS)
  2. Convert the PS back into PDF (File: Create PDF from File, choose the PS)

Pretty simple! Since I didn’t find any results for it in my search I decided to post it. Hopefully it might come in handy for someone else out there.

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8 Responses to Removing Signatures from PDFs in Acrobat Pro 9

  1. open September 27, 2012 at 4:45 pm #

    Thank you!
    It works like a charm! :)

  2. Gazu October 26, 2012 at 7:17 am #

    You were a godsend! I had the same trouble and this solution was so easy it scared me.

  3. enrique December 31, 2012 at 11:43 pm #

    thanks for the worst advice. lost my form.

    • Paul Erdman January 2, 2013 at 10:48 am #

      Enrique, I had not anticipated this workflow being used on a form. You are correct. PostScript does not support form fields. I’m very sorry my article did not address this; I’ve ammended the article based on your experience and to keep other readers from running into this problem.

  4. Patrick May 8, 2013 at 10:33 am #

    Problem – when exporting a pdf with many form fields all the fields disappear when you convert it back to pdf. Then you have to go througth the whole procesws of re-creating the form fields- just as much of a pain as trying to figure out how to unlock the dang sig field.

    • Paul Erdman May 8, 2013 at 10:46 am #

      True. Form fields and other interactive content (including signatures) are not supported in PS. Another reader already brought this up, and the article begins with an edit explaining this. ALL interactive elements will be removed, not just the form fields. If you’re working with a form, you’re best bet is to obtain an unsigned copy of the form from the original creator of the document.

  5. Eve May 17, 2013 at 3:38 am #

    Not sure what am I missing here.. but it did not work. I had signature field on my original PDF, I wanted them to be removed. Tried your post-script method, when converting back to PDF it shows result “This PostScript file was created from an encrypted PDF file. Redistilling encrypted PDF is not permitted.”.
    The only thing I could do is, click on the Signature panel, check on the 1st person’s signature and “Click to view this version” so it revert back to the earliest version, all other people’s signature that placed after the 1st person will be gone; but the first person’s signature still in place.. unable to remove it completely :(

    • Paul Erdman May 23, 2013 at 10:09 pm #

      This error typically indicates that the file has security enabled, in addition to signature fields. Acrobat will not allow re-distillation of a file that has security enabled.

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