Acrobat & PGP Keys
Does anyone out there know if there is a practical way to sign PDFs to enable me at a later date to determine if a PDF has been tampered with?
I know you can password protect them etc but what I want to be able to do is create a PDF and then if needed at a later date get that PDF back from a client and verify that the signature is mine (or my companies), and that they aren't using a modified (or otherwise regenerated) PDF.
Preferably this could be done with existing GPG (PGP) Keys.
Adobe Acrobat (Not the free Reader) has a method of digitally signing the documents that not only adds an encrypted digital signature to the document but you can also include a scanned copy of your own handwritten signature to the line. We've used it here for various things. Once it is signed it has many of the same functions as doing the password protection that you've spoken of.
Originally Posted by thorin