I have a form created in Word 2010 that is stored on SharePoint. I have a requirement that all users in my organization will digitally sign this form if they use it. I am completely new to digital signatures so can somebody please explain it to me what is required to do be able to do this? Documents are only used internally. Do we need to purchase something or can we do it somehow internally? Do I need to install anything on all of the computers? Thanks!