But what if we instead design the system so that the leaked radio signal has zero mutual information with whatever signals are passed around inside the system? Then it doesn’t matter how much optimization pressure an adversary applies, they’re not going to figure out anything about those internal signals via leaked radio.
Flat out wrong. Its quite possible for A and B to have 0 mutual information. But A and B always have mutual information conditional on some C (assuming A and B each have information) Its possible for there to be absolutely no mutual information between any 2 of electricity use, leaked radio, private key. Yet there is mutual information between all 3. So if the adversary knows your electricity use, and can detect the leaked radio, then you know the key.
Flat out wrong. Its quite possible for A and B to have 0 mutual information. But A and B always have mutual information conditional on some C (assuming A and B each have information) Its possible for there to be absolutely no mutual information between any 2 of electricity use, leaked radio, private key. Yet there is mutual information between all 3. So if the adversary knows your electricity use, and can detect the leaked radio, then you know the key.