# Journey into Cryptography

1 program
8 videos
5 talkthroughs
1 skill
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? <br> Questions: <br> 1. Why do we follow this pattern without thinking? <br> 2. Would it be different for different languages? <br> 3. How could we ...

### Polyalphabetic cipher

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

### Polyalphabetic Exploration

Try out a polyalphabetic cipher

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.

### Frequency Stability Exploration

Can you fake a coin flip?

### Coin flip sequences

Determine if a sequence of heads and tails was generated with a fair coin, unfair coin, or human guesses.

### 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