An introduction to cryptography, internet security, and cryptocurrency, beginning with an overview of RSA cryptography and covering the use of public and private keys and their incorporation into the Transport Layer Security protocol used for secure internet communications. We then examine the key features of cryptocurrencies, including the blockchain, proof of work consensus mechanism, the use of hash functions, and the role of crypto mining. We conclude with a discussion of some of the advantages and disadvantages of cryptocurrencies, including their anonymity, volatility, use in crime, and environmental impacts. If you enjoyed the podcast please consider supporting the show by making a PayPal donation or becoming a Patreon supporter. https://www.patreon.com/jamesfodor https://www.paypal.me/ScienceofEverything