Right, but the goal isn&#x27;t to make a strong or useful encryption tool. The goal is to show that cryptography is, at it&#x27;s core, rather simple. It&#x27;s simple enough that we can cram &quot;real&quot; symmetric encryption into the size of a tweet.<p>It&#x27;s like building an electric motor out of some scrap wire and some fridge magnets - the motor isn&#x27;t really useful for anything, but it teaches the basic idea in a way that anybody can appreciate. A useful motor would have bearings, a commutator, multiple windings, an iron core, etc., but adding all that stuff just obscures the basics. Criticizing a school-kid&#x27;s motor for being weak and inefficient is completely missing the point.<p>This program isn&#x27;t supposed to be useful. It&#x27;s supposed to prove a point.