Hello Everyone, We have a windows application in (the dot net 2.0 framework). Using this application our client took out invoice print. Due to the new gov. rules and regulations, they want to take out digitally signed invoices in pdf format so they can upload them on the gov. portal. Every client will have their own one or multiple "DSC token/ e-pass token 2003/smart card" given by emudhra. We have to use this USB token to digitally sign the pdf. I want to ask that has anyone worked and digitally sign the PDF document using a USB token I need your help in this task. What I did : I can add a digital signature in pdf using a pfx file but as discussed with emudhra USB token and a pfx file are two different things. Sir, I need your help to accomplish this task.