Almost overnight, a new currency called bitcoin is being traded in exchange markets and its dollar value has been rising roughly exponentially since about 2012. Bitcoin and blockchain, the universal ledger where bitcoin transactions are recorded, are leading the cryptocurrency revolution. This course covers the mathematical, computational, and economic foundations of blockchain, and exposes students to the societal and legal implications of a decentralized monetary system based on consensus. Students learn what bitcoins are, why it is possible to make money using bitcoins, and why it is so volatile. Through practice with bitcoin and Ethereum-based software platforms, students build decentralized applications, develop an understanding of cryptographic principles, and revisit critical economic questions, such as what is money, what is a transaction, and who should authorize a transaction.