After opening the signed document with Adobe Acrobat Reader, do you get the warning "There are problems with at least one signature"?
In this case, a certificate was used for signing, which was classified by Adobe as not trustworthy or could not be completely verified. Therefore, the identity of the signer is "unknown" and Adobe displays a warning.
There are several ways to bypass this warning:
- You are using the eIDAS Pad Signature Seal. The certificate used there is known and trusted within the EU in Acrobat Reader. This means that the recipient of the PDF document signed with it immediately has the "green tick" in Acrobat Reader and the document enjoys the highest level of trust.
- You add the signature certificate manually to the trustworthy certificates (must be done at each recipient).
You can do this as follows:
"Right click on a signature > Show signature properties... > Show issuer's certificate... > Trustworthiness > Add to trusted certificates...".
Please confirm all dialogs with OK and verify the signature again. Now the message "Signed and all signatures are valid" should appear.
This setting can also be configured company-wide, e.g. via a domain.
Our sales team will be happy to answer any further questions you may have.