Shoutbox

I've got a program that we use here at uni that i'd like digitally signed so that when students run it, they see the name of our college displayed, rather than just "unknown publisher"

I've had a search around for how to do this and it seems like I need to include a .pfx file

http://www.chilkatsoft.com/p/p_218.asp

that link gives details on how to do it once I have the pfx file.......but I'm not sure how to get a pfx file

Is it something I can create...or something that needs buying?