3 ms·
That is really cool. I'm surprised, though, something at the femtofarad level doesn't suffer from big swings in behavior/signature based on ambient temperature
by tyingq 4y ago
That is really cool. I'm surprised, though, something at the femtofarad level doesn't suffer from big swings in behavior/signature based on ambient temperature, moisture, general surroundings, and so on.
- amelius 4y agoSome pressure sensors use the same underlying technique :)
- deleted 4y ago[deleted]
- tyingq 4y agoAh, so add altitude and barometric pressure then :)
- amelius 4y agoI was thinking of touch-pressure, but yes.
- tyingq 4y agoI meant as outside influences that could make using the reading as a cryptographic signature difficult. That is, they are measuring something to do with capacitance (at a very small "femto/10^-15" scale) at the place where they seal it up. Then you're supposed to be able to do that same measurement at the place where it arrives after shipping, and have identical readings. Even though origin and destination likely have different ambient temps, humidity, altitudes, and so on.
- amelius 4y agoOk, I see what you mean.