Today’s devices have been secured against innumerable software attacks, but a new exploit called Plundervolt uses distinctly physical means to compromise a chip’s security. By fiddling with the actual amount of electricity being fed to the chip, an attacker can trick it into giving up its innermost secrets.
It should be noted at the outset that while this is not a flaw on the scale of Meltdown or Spectre, it is a powerful and unique one and may lead to changes in how chips are designed.
There are two important things to know in order to understand how Plundervolt works.
The first is simply that chips these days have very precise and complex rules as to how much power they draw at any given time. They don’t just run at full power 24/7; that would drain your battery and produce a lot of heat. So part of designing an efficient chip is making sure that for a given task, the processor is given exactly the amount of power it needs — no more, no less.
The second is that Intel’s chips, like many others now, have what’s called a secure enclave, a special quarantined area of the chip where important things like cryptographic processes take place. The enclave (here called SGX) is inaccessible to normal processes, so even if the computer is thoroughly hacked, the attacker can’t access the data inside.