I've been needing to sign PDFs lately - fortunately everyone's been fine with me using a self-signed certificate, however I feel it's unprofessional. I'm looking for a personal certificate I can use to sign PDFs and other documents (such as emails).
I saw that GlobalSign.com offer "Digital Signatures for Microsoft Office" at a reasonable $90/year for their "PersonalSign 2 Pro" product, or even $30/year for their email-validation only "PersonalSign 1" product.
They also offer a separate PDF-signing product which is two-factor and comes with a USB token, this product is considerably more expensive, at $370/year.
I don't understand this - a certificate can be marked as trusted for document signing, but as far as I know there is no per-application restriction inherent in certificates that says "you can use this in Office but not Acrobat", indeed when I open Acrobat Pro it lets me use any certificate on my machine to sign a document.
I spoke to their Live Chat support, asking if I can use an Office certificate for Acrobat and she replied, saying only the more expensive PDF signing product has a "key-usage" field set to allow PDF signing. I didn't want to debate this further as it looked like she was copy+pasting from their website, but I'm still not satisfied how this seemingly arbitrary restriction is implemented.
If suppose if I had more free cash I might drop the $90 for the "PersonalSign 2 Pro" product and try it to see if it works, but I don't want to risk potentially having my refund request denied if Acrobat doesn't work with the certificate.
Can anyone testify what certificates can be used for PDF signing?