# Journey into Cryptography

8 videos

6 talkthroughs

Explore how we have hidden secret messages through history.

### What is cryptography?

What is Cryptography? A story which takes us from Caesar to Claude Shannon.

### The Caesar cipher

Brit explains the Caesar cipher, the first popular substitution cipher, and shows how it was broken with "frequency analysis"

### Caesar Cipher Exploration

Type a message in the top box, then click and turn the wheel to encrypt it.

### Frequency Fingerprint Exploration

Did you know that when you communicate you are following a pattern without realizing it? Questions: 1. Why do we follow this pattern without thinking? 2. Would it be different for different languages? 3. How could we avoid this?

### Polyalphabetic cipher

Brit introduces the polyalphabetic cipher, which creates a lighter fingerprint than the Caesar cipher.

### Polyalphabetic Exploration

Try out a polyalphabetic cipher

### The one-time pad

The perfect cipher

### Perfect Secrecy Exploration

Explore how random shifts flatten your frequency fingerprint

### Frequency stability property short film

Can you tell the difference between actions based upon flipping a coin and those based upon blind guessing or simulating randomness? This short video examines the frequency stability property.

### How uniform are you?

Input a long list of 0's and 1's into the text field with your EYE'S CLOSED - how uniform are you?

### The Enigma encryption machine

WW2 Encryption is explored with a focus on the Enigma. Read more here.

### Perfect secrecy

Claude Shannon's idea of perfect secrecy: no amount of computational power can help improve your ability to break the one-time pad

### Pseudorandom number generators

Random vs. Pseudorandom Number Generators

### Random Walk Exploration

generate pseudorandom vs. random walks