Sir Osis of Liver 🇨🇦
🇲🇽
@Sir_Osis_of_Liver@beige.party
@arclight@oldbytes.space
There was one utility I worked with that maintained all of their transmission and distribution logic as hard wired discreet logic.
Need to change breaker closing sequence? An electrician would be dispatched to the switchyard to physically re-wire the logic.
Their SCADA was for monitoring only, and completely segregated from the internet.
At the time I thought it was really odd and old fashioned. Now, I'm convinced they had the right idea.
Poul-Henning Kamp@bsdphk@fosstodon.org
@Sir_Osis_of_Liver@beige.party @arclight@oldbytes.space
It used to be a fundamental principle of any process control, that you would have "actuators" and "indicators".
And the indicators would show you the present situation, 100% independent of the actuators.
Today they are combined into a single program on a Windows PC.
... Which is precisely why StuxNet could keep the iranians in the dark for so long: They hacked the indicator part to show what the actuators were set to, instead of what happened.