The Purdue Model of Security

The physical architecture still very much follows the preview model. Each one of those layers is a different security requirement that you have to reach in order to be able to move up to the next layer. You know, I have no way of patching a PLC easily so everything that's in my production network is as isolated as I can make it and don't let it communicate with anything other than my kept server or an IoT gateway. So how do you patch stuff that you never patch, right? And this company by trail there, they hope their focus is to keep our PLCs, our edge devices, our HMIs, all that stuff on the latest firmware versions in real time without