S-boxes should be balanced (equal number of 0s and 1s in the boolean function truth table) Boolean functions must be non-linear Single bit changes on the input cause changes on 1/2 of the outputs Good ...

This gets into the Boolean weeds a bit, and we won’t pretend to fully understand it, but at least for this case, [Dr. Shane] was able to add a single AND gate to sum the two other inputs and ...