Can cryptography be the basis for a new financial system? This is what cryptocurrencies have been trying to answer since at least 2008, when Bitcoin was proposed by Satoshi Nakamoto (who to this day has yet to reveal his or their identity). Before that, the term crypto was always used in reference to the field of cryptography. But since the creation of Bitcoin, I have seen its meaning quickly change, now being used to refer to cryptocurrencies as well. Cryptocurrency enthusiasts, in turn, have become more and more interested in learning about cryptography. This makes sense as cryptography is at the core of cryptocurrencies.