Encrypt Sign Presentation Safe

Encrypt Sign Word Safe

This episode is supported by NordVPN. Start protecting your internet experience today with a 3-year VPN plan. Get 75% off, plus 1 month free by using the code“SCISHOW” at NordVPN.comSCISHOW. [ intro ] It’s 406 BCE. You, the commander of Sparta’s navy, have a top-secret message for your magistrate back home: the new strategy to defeat those dastardly Athenians is to cut off their grain supply! But wait…what if your messenger gets captured? Athens might see your message and head off your plan! The standard Spartan solution was a scytale—a wooden rod paired with a strip of leather. You’d wind the leather around the rod and write your message line by line. When you unwound the leather, the letters would look like a meaningless jumble to anyone who didn’t know the width of the rod. Of course, all you’d have to do was try a bunch of different thicknesses until the letters turned into words, so it wouldn’t be an especially difficult code to crack. Over the centuries, people have tried to do better, coming up with more and more sophisticated ways to encrypt, or scramble, information. Most of these encryption methods weren’t perfect—there was always a chance that an attacker would manage to undo the procedure you used to encode the information. But with the help of computers, we now have ways to encrypt information that are almost impossible to crack. That’s a very good thing, because encryption is what protects your bank password from hackers, keeps prying eyes out of your WhatsApp messages, and even makes sure those Windows updates really came from Microsoft. The weird thing, though, is that these practically-unbreakable codes are still based on the same building blocks the ancient Greeks used — with just a couple of twists. Any coded message has two main parts: The first component is the cipher—a scrambling procedure like the scytale, which is meant to mash up the message into something unrecognizable. The second component is the key—some secret, like the diameter of the scytale, that keeps unauthorized people from unscrambling the message. In modern encryption, the process of sharing keys can be kind of involved. And it definitely involves way more math than before computers were a thing. But none of that matters unless you have a usable cipher that can’t be cracked. Those have only existed for a few decades, but they’re built on the same ideas we’ve been using for centuries. In fact, many modern ciphers just involve taking the two main types of classical ciphers and applying the techniques a little differently. One type of classical cipher is the transposition cipher, where the key tells you how to reorder the letters in the message. The scytale was a simple version of that. A more sophisticated example of a transposition cipher is the route c ipher. Say you wanted to encrypt a message telling the Spartans back home to “cut off the grain supply.” You’d write it down in a grid of, say, 5 columns, then...