In Scott Aaronson&#x27;s book Quantum Computing Since Democritus, he off-handedly mentions the need for quantum-hard crypto and that perhaps something based on Wolfram&#x27;s cellular automata would do the trick. Wolfram says he used one of his own cellular automata rules as the PRNG in Mathematica. Which makes me wonder, why don&#x27;t we already use something like this in modern crypto? And, how exactly would we implement this if we wanted to do so?