Re:ECDSA smartphone key extraction using $2 magnetic probe
by korethr on Friday March 25, 2016 @02:22PM
(#11361753)
It still strikes me as plausible. Sub-harmonics are a thing; it is entirely possible to leak data about what the CPU is or isn't doing down into the ultrasonic or audible bands.
As an example, one of my computers leaks a ton of noise into the onboard audio that quickly becomes audible with a moderate amount of gain. So much so, that I've learned to recognize changes in the noise pattern from various activities (shuffling windows around the gui, launching a program, compiling a program, etc).
How practical a real-life, working use of the method described here will depend in no small part how much noise the device being attacked casts off. There's some pretty bad devices out there.
As an example, one of my computers leaks a ton of noise into the onboard audio that quickly becomes audible with a moderate amount of gain. So much so, that I've learned to recognize changes in the noise pattern from various activities (shuffling windows around the gui, launching a program, compiling a program, etc).
How practical a real-life, working use of the method described here will depend in no small part how much noise the device being attacked casts off. There's some pretty bad devices out there.