Cracking keys while decryption


#1

Howdy!

I wanna start with learning SCA and was wondering if chipwhisperer can be used on a product that is decrypting stuff (instead of encrypting) like over another chip. which I can send data over serial to and view power traces.


#2

Hi Brady,

Side channel analysis definitely works against decryption, too. The attack is a little bit different, but the idea is the same as encryption: if there’s a non-linear operation (like SubBytes in AES) then you can still attack it.

Have you looked at Tutorial A5? This guide walks through an attack on AES-256 decryption, which isn’t much more complex than AES-128.