Validating digital signature
You also won't be able to manually validate the signature until the certificate is trusted by Adobe.To resolve this issue you need to make Adobe trust the certificate that was used to sign the PDF.I can sign the pdf fine using the cert but when another user opens the document I get the error "At least one signature has problems".
Signer's identity is unknown Digital signatures that were added using what's called a "self-signed certificate" — usually a certificate that you have generated yourself using a third party application — cannot be automatically validated by Adobe because the certificate is not in the list of Trusted Identities that Adobe uses to validate signatures.
It's important to note that this message is not saying that your digital signature is invalid and it's not saying that the PDF has been modified since it was signed (see the text in the screenshot above: "Document has not been modified since this signature was applied"), it's just saying that Adobe wasn't automatically able to validate the certificate.
You don't need to purchase a Digital ID certificate to self-sign documents electronically with Revu, but if you decide you need a third party certificate authority (CA), these services are known to work with Revu.
Since implementing Bluebeam into our plan review process, we have measurable results.
Similarly, a digital certificate or Digital ID issued by a third party, Certification Authority (CA), such as Veri Sign and Geo Trust, serves the same purpose.