I know that we need to generate a delta-set (with 256 plaintexts).
During the attack, we guess 4 bytes of round 5 key and 1 bytes of round 4 key, which allows us the byte at one position of the state at the end of round 3. If that position is balanced, then the 4-byte prediction is valid, but there are a lot of false-positives.
My problem is that there are too many false positives. No matter what delta-set I generate, all remaining 4-byte combination result in a false-positives.
How can I generate the input plaintexts to eliminate these false positives? I can't find a single implementaion of AES Square attack online, so if anyone can show me, I'd be very grateful.
Thank you.
Edit: nevermind. On average 5 delta-sets or less is needed. I just had a data-type bug (char -> unsigned int) that make the program fail to eliminate delta-set