Comment by palmotea
16 hours ago
> Getting lucky and drilling through a part of the enclosure that isn't directly protected won't help you if a barometric pressure sensor is tripped as a consequence of breaking the hermetic seal.
That's interesting. I suppose if that technology is in use, the attack would have to occur in a pressure-controlled chamber, so breaking the seal wouldn't cause a change in pressure.
A more likely measure, which I recall seeing years ago, is to measure the impedance of the enclosure of the thing you want to protect. If someone tampers with it, you would be alerted. It works at many scales, from a protective metal mesh over your IC to a PC case.
And you'd need to have a way to know what the pressure inside is beforehand.
You can find the pressure through destructive trial-and-error if money is no object - which it isn't for governments when the target hardware is juicy.
Why would you make each device have the same pressure inside it? That's a bit like hardcoding the same password in each one. Any attacker is only going to have one shot on the actual device they care about no matter how much money they spend.
Really sounds very very easy for any lab that can measure molecular levels of gas.
Even a very sensitive pressure checker in a temp controlled sealed box would do it.