Congratulations - excellent work!
Seriously - nice job. That is some impressive, impressive work.
As several people have mentioned above, EMI is one thing (and a pretty well known thing) but using coil whine* as a reliable indicator of what functions the CPU is performing and refining that to find a 4096-bit key? Like I said: impressive.
Of course, they then took this further, realising that, as the source of information was seemingly voltage regulation, there should be ways to measure this more directly. In one of their experiments they get the same information from connecting a voltage probe to a CAT5 cable connected to a switch - at the switch end. As they rightly point out, that can be in another room, far from the user's gaze and doesn't actually interrupt use of the network. As the information is coming from the potential of the shield, you don't even need the port to be enabled on the laptop.
Even more amazing is being able to measure this indirectly by measuring the potential of someone touching the laptop chassis!
Again - very, very impressive work and they should be suitably proud of it.
Maybe not directly useful given the restrictions but they have proved a general property - that CPU operations can be reliably ascertained from analysing the voltage regulation.
* - What people call 'coil whine' is not always generated by the coils themselves, as the paper identifies. More generally, it is the power supply/regulation circuits that are responsible. It doesn't seem to matter what is actually responsible, nor that they know what component/circuit it is.