Do I need to buy an Adobe CDS certificate to sign PDF documents? It can be confusing for PDF users to decide what certificate to buy to secure their PDF documents.There is not much information out there because certificate authorities and companies like Adobe make good money selling certificates. Adobe just wants you to buy the Adobe CDS certificates of course!

They don’t want you to know that all certificates are pretty much equivalent when it comes to the technical side of signing PDF documents. The fact is that when you digitally sign a PDF document, the document is encrypted and secured regardless of the origin of the certificate. If any changes are made to a signed document, regardless of the certificate, the signature will be invalidated and all PDF viewers will be able to identify and display that “Changes were made to the document after it was signed“.

The difference in certificates lay in the price and the fact that some certificates will be automatically recognized as being issued from a valid authority in tools such as Adobe Reader. So basically you are paying simply for the “recognition” of the root authority.

Here are the 3 choices with their different price options:

–  Buy an Adobe CDS at $369 a year from a certificate authority such as GlobalSign or Verisign. Your signature will be validated in in Adobe Reader.

–  Buy a Microsoft Document Signing at $30 a year from a certificate authority such as GlobalSign or Verisign.

Your signature will be validated in Adobe Reader, under Windows, if your readers have turned on the settings “Trust ALL root certificates in the Windows Certificate Store” for Validating Signatures under Edit->Preferences->Signatures->Verification. This is because the certificate authority who issued the certificate is a root certificate in the Windows store.

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–  Create a self-sign certificate for free. Your signature will only be validated in Adobe Reader if your readers decide to trust your certificate. Your document is still encrypted and the signature information will display if the document was or wasn’t modified.

Adding PDF Digital Signatures with PDF Studio:

PDF Studio, Qoppa’s PDF editor is an affordable option to apply real official digital signatures to PDF documents.
PDF Studio works on Mac, Windows and Linux.
Windows and Mac certificate stores are trusted by default.

Keywords: Expensive, cheap, digital ID, certificate, sign PDF, PDF file.