Adobe Reader Signature Validation : How to Validate Signature of a PDF Document

When you open a PDF document with having a digital signature, it shows

Validity unknown
Digitally signed by
signer's name
Date:

If you click on the Signature, it will show the "Signature Validation Status" saying that

Signature validity is UNKNOWN.
-The Document has not been modified since this signature was applied.
-The signer's identity is unknown because it has not been included in your list of trusted certificates and none of its parent certificates are trusted certificates.

So here is the way how to add a signature to trusted list in Adobe Reader to validate signature and also how to remove a trusted signature.



To add a signature to trusted list in Adobe Reader follow the steps below:

• Open the PDF Document and Click on the Signature to be Validate

• Click on Signature Properties

 

Signature Validation Status Adobe Reader

•  Click on 'Show Signer's Certificate'

 

Signature Properties (Show signer's certificate)

• On the Certificate Viewer Click on Trust Tab then Click on 'Add to Trusted Certificates'

 

Add to trusted certificates

• Now you will get a Acrobat Security Warning Click OK

• On 'Import Contact Setting' window the 'Use this certificate as a trusted root' option should be checked then Click OK.

 

Import Contact Setting Adobe Reader

That's all now your have a valid signature for the PDF document, go back to your document you will see a Green Colour Tick Mark on the Signature Place.

Signature Valid Adobe Reader