Validating Digital signature in Any PDF Reader

To validate a PDF signature, you'll need access to the PDF document that contains the digital signature, and you'll typically use PDF software or libraries that support digital signature validation. Here's a general guide on how to validate a PDF signature

1.  Open the PDF document in a PDF viewer or editor that supports digital signature validation. Adobe Acrobat Reader is a widely used application for this purpose.
2. Find Question mark in yellow color somewhere down in PDF document as shown in this image and left click on it.
   
3. A new window will appear as shown below. Click on Signature Properties...
   
4. In Signature Properties window click on Show Certificate...
   
5. In Certificate Viewer window click on Trust Tab and then click on Add to Trusted Identities... and then click OK button on Adobe Securities popup as shown in below images.
   
   
   
6. Now Import Contact Setting window will open set check boxes as shown in below image and then click on ok again ok and last click on Validate Signature:
   
   
7. And Now Signature icon status is changes :