Explore how we have hidden secret messages over time. Brit Cruise discusses the basic idea behind why we need cryptography, the fundamental theorem of arithmetic, and basics of what a probability space is.

He also asks if humans can generate truly random sequences, explains the Caesar Cipher, creating a lighter fingerprint with a more intricate word-based cipher, WW2 Enigma machine – the theory behind how it worked and why it was broken.

Claude Shannon’s idea of perfect secrecy is introduced. No amount of computational power can help improve your ability to break a perfectly secret encryption scheme.

Brit talks about random vs. pseudo-random number generators, Diffie-Hellman Key Exchange, RSA Public Key Encryption Algorithm. How and why it works. Euler’s Theorem, Euler’s Phi function, prime factorization, modular exponentiation and time complexity.