[dsyko]

I believe they are suggesting that the above comment "Short of a oscilloscope hiding in the computer you use" might not be so far fetched. The hardware needed to do the type of analysis used for this attack has been around a long time and is presumably very cheap at scale. So if for example a nation/company that has control over the manufacture of a large number of USB controllers decided they wanted to be able to do this kind of power analysis on all USB devices plugged into their controllers they could do so easily.

Esentially adding a micro controller with an Analog to Digital converter that can watch the power pin inside the USB controller/port itself would be relatively simple and cheap.