John MCAFEE
https://www.google.pl/search?q=learn+crypto&client=ms-android-xiaomi&biw=360&bih=564&tbm=isch&prmd=vin&source=lnms&sa=X&ved=0ahUKEwjBkMns19fcAhVDZ1AKHQauBGkQ_AUIECgC#imgrc=Hyjtx-A7wJ7TSM: