In my earlier column on the philosophy of Defense in Depth, I discussed how relying on a single defensive solution exposes a system to a single point of failure. No matter how well designed or strong that single defense is, either resourceful adversaries or Murphy’s Law eventually results in the defense malfunctioning or being bypassed. When that happens, the entire system is wide open to attack.

In my blog article Industrial Data Compromise – The New Business Risk, I recommended that End Users and Control Engineers need to redouble their efforts in relation to securing their process. However, finding the best way to justify the costs of implementing and maintaining a more secure process environment is new territory even for the most seasoned control system engineer. In this article I suggest a way to determine the right amount of investment in ICS and SCADA security measures.