Is there a circuit/adapter which allows injecting negative voltage faults? That is, instead of bringing the voltage to 0, I’d try to bring it below zero.
There’s a paper detailing the motivation behind the idea and also a possible implementation, “Design and Implementation of a Negative Voltage Fault Injection Attack Prototype”. I realize I can (and likely will) probably simply use a MOSFET, controlled by the CW glitch output, and a positive-to-negative voltage regulator, but I’d like to hear some more opinions about the prospective circuits and other pros and cons.
Riscure’s Spider tool offers controlling the glitch floor voltage down to -4 volts, and there are some papers showing benefits of that practice.
why dont you just swap resistance from vcc line to gnd in chipwhisperer lite ? , i think it should generate crowbar glitch on gnd line by that way…
do it and let us know also i think you can veriffy if it works or not just measure effect by oscilloscope in ac coupled mode
you see on the top photo you have positive (vdd crowbar glitch) and on the bottom photo i swapped resistor from vdd to gnd , and i think it should work like that and create negative gnd glitch
someone correct me if i am wrong ? , also not sure about how negative gnd glitch can be measured by oscilo…
I am currently not using resistance for my glitching setup, because I am glitching the output of an internal regulator.
I think if you put a resistor on the source side, connected to ground, the effect will be that you will raise the chip ground reference in the moment of glitching. That’s because the glitch current will pass through the resistor, inducing a certain voltage.
also i think you can veriffy if it works or not just measure effect by oscilloscope in ac coupled mode