Configuration and usage of the certificate in Adobe Reader (Adobe Acrobat)
You can use an S/MIME certificate (see here for further information) to digitally sign a PDF document. During the process of certificate application your identity has been verified, so you can use it to provide documents with an advanced electronic signature according to the eIDAS regulation.
Below you will find instructions (for Windows; other operating systems slightly different) on how to set up Adobe Reader (also applies almost identically to Adobe Acrobat) and use it for digital signing.
Before you can use the certificate in Adobe Acrobat/Reader, you must first set up the program(s) accordingly in four steps:
If all steps to set up the certificate have been carried out, all requirements are met to sign a pdf document with your personal certificate. In a short instruction we describe how to do this.
An electronic signature must be checked for its validity and should exclude any manipulation of the document. This check determines whether a valid certificate and the time stamp service were used and whether the document was not modified after the signature. We have provided brief instructions on how to proceed here: Validate electronic signature.
"Signed and all signatures are valid"
"There are problems with at least one signature."
"At least one signature requires validation"
"[...] but with unsigned changes after the last signature"
"Document was updated after signing [...]"
"Signature validity is UNKNOWN"
The "Sign digitally" field is grayed out
"The credential selected for signing is invalid"
"Errors occurred while signing"
If you have any questions or problems, please contact the RRZK-Helpdesk