Digital Signature Certificates and Validation

When you open a digitally signed PDF, it will alert you that the signature needs validating. Personally, I’ve sent dozens of digitally signed PDFs. No one has asked to validate my signature. I think there are two reasons for this:

(1) My digital signature looks like my “wet” signature (see tutorial on creating a digital signature).
(2) Most users aren’t familiar with digital signatures and despite the alert, don’t bother to validate. Even if they do, they have no idea how to make sure the signature is valid, other than the sender’s word.

In a business workflow, it is important to validate digital signatures. It’s similar to showing your ID when using a credit card. It’s easy to do. Simply send the certificate that was generated when your digital signature was created.

Here’s how:
 When you open a digitally signed PDF, a blue bar appears above the page noting the signatures have not been validated. To validate the signature, click the Signature Panel button to open the signature panel, and click Validate All to validate the signature. If there is no certificate to validate the signature, a note will appear that the signature has a problem. If a digital signature certificate is available, the signature is noted as valid.

To ensure the recipient can validate your signature, send your certificate. This is easy and can be done from the free Adobe Reader and a full version of Acrobat.
Reader: Document > Security Settings
Acrobat: Advanced > Security Settings

Select Digital IDs > Export

At this point you can directly email the certificate to the recipient or save it and email it later as well as send it to other recipients.

Select Email or Save the certificate.

Selecting Email generates an email with a pre-composed Subject and message. Add the To: email address and click Email. The message can be edited as desired.
Select Save the certificate as a file and the Save As dialog appears to save the.FDF file for later email or exchange.

In a corporate environment, saving the certificate and storing it in a folder, on a server, that is available to everyone in the company, will enable in-house signature verification. This is an excellent way to begin implementing a digital signature workflow.

When the recipient receives the email with the attached certificate (as noted in the email message), double-clicking the FDF Data Exchange File will start Acrobat and load the certificate. The recipient will now be able to verify your digital signature.