Explore the fascinating world of cryptography and its evolution in this lecture by Professor Cris Moore of the Santa Fe Institute. Delve into the history of secret codes, from Caesar's simple letter-shifting technique to the complex Nazi Enigma machine. Discover how modern cryptography relies on prime number mathematics and learn about Peter Shor's groundbreaking discovery regarding quantum computers' potential to crack current cryptosystems. Gain insights into the workings of public key encryption, modular arithmetic, and factoring large numbers. Investigate the concept of quantum computers and their implications for future cryptography. Examine error-correcting codes, symmetry in cryptography, and the potential for new secure encryption methods in a post-quantum world. No advanced mathematical knowledge required – this talk is accessible to anyone with a high school math background.