I forwarded this to my dad who still works on RPG. This product is called "Software Sentinel": > It required an input key that was unique to our dongle series

I forwarded this to my dad who still works on RPG. This product is called "Software Sentinel": > It required an input key that was unique to our dongle series & our own code that was whatever we wanted. The reply was a hash of both values. > The last version we used was USB. They retired the parallel style long ago.