Nicola Salmoria was able to decrypt a complete CPS2 game algorithmically without using any table!
Well, to be fair Andreas Naive played a key role here. Andreas started with the Feistel Network theory and lead the break out. It is amazing what you can get making two genius work together!
In case you haven't heard of Andreas, he's a very clever spanish guy that also helped to reverse engineer the DSP-1 chip used in Mario Kart and the S-DD1 used in Star Ocean.
There are some pieces of the puzzle to complete to fully understand the encryption but having reached that far it can only get better
Take a detailed look at their blogs to know more about this amazing achievement!
Hats off to you guys!