Changing the AES key

Hello, I am currently running the PA_DPA_3-AES_DPA_Attack tutorial. I Get it to work the way I want but I would like to try and change the AES key and check if that works too. I’ve tried changing DEFAULT_KEY in aes-independant.h and recompile everything but that does not work for me, I still get the original key. How Should I go about doing this?

Hi,

To use a different key, modify the key variable in the final block in the code copied from the hardware file: https://github.com/newaetech/chipwhisperer-jupyter/blob/master/courses/sca101/Lab%203_3%20-%20DPA%20on%20Firmware%20Implementation%20of%20AES%20(HARDWARE).ipynb

Hi Alex,
Before I was setting new key via this:

ktp.setInitialKey(“75 db 2c 11 f8 f2 3a 6b ee de 22 22 7f 3a f0 9d”)

what’s the difference?

3

Hi 3,

The only major difference is that your method will set the the key in the actual KTP class, whereas my method just modifies the key variable. Thinking more about it, that’s probably a better way to do it (less chance of accidentally resending the original key), it doesn’t make a huge difference either way.

Alex

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