***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:
- Export the PDF as a PostScript file (File: Export: PS)
- 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.