In my last blog, I discussed the reasons why critical industrial infrastructure control systems are so vulnerable to attacks from security researchers and hackers, and explained why patching for such systems is not a workable solution.

But let’s now examine the good, the bad and the ugly details of patching as a means to secure SCADA and ICS systems. And to begin, let’s suppose patches could be installed without shutting down the process (for example, through the staged patching of redundant controllers)…