This is a question that might not even emerge initially in the minds of IT security professionals. However, when we take a closer look, the differences are clear. Consider the history of IT and SCADA networks. The original “killer app” for IT networks was mainframe transaction processing. The original model for IT systems was a leger book – keep track of the money. The data in the leger book is what was important. This perspective continues to this day. Where did SCADA networks come from? Before there were SCADA networks we controlled physical processes with switches, dials and gauges. When