2 Replies Latest reply on Aug 20, 2008 10:04 AM by (Suzanne_Cole)

    Confused about digital signatures

      Please refer to this archived thread:
      http://www.adobeforums.com/webx?128@@.59b4d8d6

      I'm researching digital signatures because we have a request form that was created in Acrobat 7.1, and that a user signed by creating his own signature in Reader 8.x. In Acrobat 7.1, I see a message when the file is opened that it has been digitally signed, and it verifies the signature. I'm trying to figure out whether that signature process would satisfy an auditor as to its authenticity.

      But according to the above thread, I'd need at least Acrobat 8.0 to "enable" a PDF to be signed. What does that mean? The form I received, by all appearances, *was* signed. It didn't need a special signature field... the signature was added over a standard text field and it was recognized and authenticated, and appeared in the signature pane in both Acrobat 7.1 and Reader 8+.

      Also, what does the 500 signature limit mean? By what process is it determined how many times a form has been used and signed? There is no tie, as far as I can see, from one copy of the form to another. The user simply saves a copy, fills it out, and sends it in. Many different people use that form (it's a work request form for IS services). Does the 500 limit apply in this scenario?

      If anyone could please advise and point me toward documentation that would help me understand how all this should work, I'd be deeply grateful.
        • 1. Re: Confused about digital signatures
          (Aandi_Inston) Level 1
          >But according to the above thread, I'd need at least Acrobat 8.0 to "enable" a PDF to be signed. What does that mean?

          It means that you need to use Acrobat 8.0 Professional or above to
          prepare a PDF in a special way.

          If this is not done, Reader cannot sign it.

          > The form I received, by all appearances, *was* signed.

          One possibility is that the person who signed it was not clear about
          what software they actually have.
          >
          >Also, what does the 500 signature limit mean?

          The EULA gives the legal details that lawyers would apply. It has
          seemed that each copy used counts towards the 500. If there is ANY
          POSSIBILITY of this limit being reached it is prudent to use Adobe's
          server enabling software instead.


          Aandi Inston
          • 2. Re: Confused about digital signatures
            Level 1
            > One possibility is that the person who signed it was not clear about
            > what software they actually have.

            Actually... I think you're right. Looking into the document properties, this PDF file appears to have been created with PDFCreator, not Acrobat at all. It appears that someone indeed has modified the file to bring it to the point where it could be signed.

            And that's grounds enough for not going any further with this, because we'd have to upgrade several Acrobat licenses just to proceed with the signatures, and there is a definite possibility of reaching 500 copies of the file, although I'm not sure how that could be tracked or who could do the tracking.

            Thanks for your time, Aandi!