I can open a password-encryption and digitally signed PDF file using Acrobat X Standard but cannot remove the password protection.
Can anyone help me remove the password encryption? The Acrobat only allows to set passsord encryption before adding digital signature to a PDF file. Can I sign a PDF file and then encrypt it with password? Thanks.
Removing the security, if it is possible, would destroy the signature.
Encrypting a signed PDF would destroy the signature.
This is because signatures validate the file exactly as it is, and changes to the file break the signature by design. Setting security is a change to the PDF (a big change).