I don't really agree with this assessment of rebase. I think there is value in squashing commits on dev branches into logically distinct sets to keep the log cleaner. In the case where the reason code is doing something that is not obvious I think that explaining the reasoning or the journey to that point in a commit message is clearer than the complete history of trial and error to reach that state.
You don't even need to understand ASCII. You can hard code an array of all the letters in the alphabet, search for a given letter and replace it with the letter 13 places ahead in the array. If you were really lazy and didn't want to worry about the logic for rolling over when going past Z, you could even rewrite the first 13 letters at the end.