2 Replies Latest reply on Dec 19, 2014 4:43 AM by mistelfink

    signature validation unknown


      After digital signing a document I get the remark in the top of the screen: "validation of document certification is unknown. the author could not be checked". I asked the company for my signature card and they checked my document with the signature. They told me that there the status of the signature is ok and they can give no assistance for Adobe Acrobat. 4 to 6 weeks before I had no trouble with signing using the same signature card, the same signing procedure of pdf - files with Adobe Acrobat XI, the same pc. I updated the program but I got still the above mentioned remark.


      Is there somebody who had the same problem and found a solution?

        • 1. Re: signature validation unknown
          IsakTen Level 4

          You most likely do not have the root of your certificate chain trusted. The string "validation of document certification is unknown. the author could not be checked" doe not look familiar. Are you back translating it from another language

          1. Check your certificate chain. Open signed PDF, right-click on the signature and select "Show Signature Properties". Then select "Show Signer's Certificate". The left-side panel of the Certificate Viewer dialog that comes up shows the chain with your certificate on the bottom and the root on the top.

          2. Select the root certificate and click the "Trust" button on the top of the right panel. If this certificate is marked as not trusted then you can click on the "Add to Trusted Certificates" button to add it to Trusted Certificates. Make sure that you know who this certificate represents so that you do not open your computer to possible malicious attacks. You can check with your IT department if this is the right think to do.

          3. Are you using some 3rd-party Acrobat plugin to sign with your smart card? I saw some instances when 3rd-party Acrobat plugins did not embed certificates in the chain into the signature object that they generated. In this case the Certificate Viewer will show only the signing certificate in the certificate chain and nothing else. This case is unlikely, though, as you said that the same signature validates fine on another computer. So, it is most likely that it is the lack of trust on your computer that causes this problem and the problem does not manifest on another computer where this trust is set.

          4. You may have gotten the file where Acrobat keeps trusted identities somehow corrupted which started to cause this problem. To check your Trusted Certificates go to Edit->Preferences->Signatures->Identities&Trusted Certificates->More. In the left panel click on Trusted Identities and look up the list of Trusted Identities in the right panel for anything missing (you may need the help from your IT for that), If your root certificate is in Adobe's AATL program you can refresh AATL certificates by going to Edit->Preferences->Trust Manager and in the "Automatic Adobe Approved Trusted Certificates Update" click on the "Update Now" button.

          • 2. Re: signature validation unknown
            mistelfink Level 1

            Dear isakten!


            Many thanks for your information. I think point 3 und 4 cover my

            problem. But I think I need some help from my son who is engaged in IT

            for actualizing my certificate.


            Peter Manner





            Am 18.12.2014 21:28, schrieb isakten:


                  signature validation unknown


            created by isakten <https://forums.adobe.com/people/isakten> in

            /Security & Electronic Signatures/ - View the full discussion