How to remove security from a PDF file?

Question

I am trying to fill out some docs, but the provided PDFs are "SECURED", meaning I can't use FoxIt's typewriter tools.

Is there any way to remove the security?

Answer 1

I used to remove passwords in the past; don't know if that's the same.

But in any case, I cannot try it out on the machine I'm writing this from, since there is neither a PDF printer in here, nor any of the readers. So all this is on a best-of-wishes basis. Try some of the softwares mentioned here (link to forum dealing with the subject).

Answer 2

Easy!

1. From the full version of Acrobat (I used v9.3), select "File..Export..Postscript..Postscript". This creates a ".ps" file.
2. Click on the .ps file, it converts it back to pdf automatically with Acrobat distiller.
3. You now have a perfect copy of the original file, minus any signatures, restrictions on editing, etc.

I needed this technique fix the pdf file so it would display on my Kindle DX, via the "Advanced..Preflight" menu. This method worked perfectly on a file that had resisted all attempts by the four major utilities that offer to remove restrictions on pdf files (i.e. A-PDF, pdftk, Kernel PDF, UnrestrictPDF) .

Answer 3

1. Print to a PostScript (PS) printer (where the printer's port is set to print to file, not to the printer -- or check the "Print to file" option in the Print dialog)

2. Edit the resulting .ps file and remove:

   mark currentfile eexec
   54dc5232e897cbaaa7584b7da7c23a6c59e7451851159cdbf40334cc2600
   ...
   cleartomark
   

3. Save and distill the .ps file

Answer 4

Analog conversion. Print and re-scan.

Answer 5

Permissions/owner password is pretty much easy to crack. This quick guide explains how to unlock a password protected pdf file

Answer 6

Assuming it's simply a 'rights' (owner) password that restricts things like editing, printing, and copying (i.e. the password does not need to be entered to open the file) the following will remove the restrictions:

1. Grab http://qpdf.sourceforge.net/
2. Unzip/Install and navigate to the bin folder that holds qpdf.exe (or similar for your platform)
3. Place the PDF you wish to work on in the same folder
4. Run: qpdf -decrypt InputFile OutputFile (use "s if the file name has spaces).
5. Do what you like with the OutputFile.

This won't work for Adobe Digital Editions, files with a user password (although if you know the password you may be able to use QPDF in the same way), and may have issues with digitally-signed files.

Some discussion on the background of these owner password restrictions at https://lwn.net/Articles/335415/ .