I would be confident in saying MITM attacks have existed even longer than encryption. - A dispatches messenger towards B. - Bad actor intercepts messenger. -

I would be confident in saying MITM attacks have existed even longer than encryption. - A dispatches messenger towards B. - Bad actor intercepts messenger. - Bad actor detains/kills messenger. - Bad actor dresses up in messenger clothing. - Bad actor delivers message to B as if they were the original messenger, having read/altered the message in the meantime.