After click on GRN Link following e - Payment Challan will open in pdf format.
(See the following Screen and go through Instructions)

e - Payment Challan


  

 

Right Click on digitally Signed symbol

Choose Validate Signature

 

Click on Signature Properties... Button

 

Signature Properties


Click on Show Cerificate Button
Certificate Viewer Popup will open

 

Certificate Viewer
Choose Trust tab


Click on Ok Button

 

See the above Signature Valid Mark.