Understanding the technology that makes cryptocurrencies possible, and an exploration of non-financial use cases for blockchain. This book presents a view of various consensus protocols, reasons for their pro and cons, explains the how and why of each part of a blockchain system, and gives a narrative view of our journey in building a novel blockchain protocol decoupled from cryptocurrencies. The increasing adoption of blockchain for non-financial use cases is currently satisfied by using technologies built with a cryptocurrency embedded in all their logic, with disastrous consequences. Blockchain systems used for the secure sharing of medical data, for tracking music royalties or ownership of art pieces, or as a base layer for supply chain and logistics, or even for a safe voting mechanism, all require a consensus system that is safe, inclusive, participatory, and egalitarian, and that bases its security and stability on network participation rather than the financial cost to perform an attack. Whether you are only interested in this new technology or are already an expert in it, you will find engaging content that will make you say "ah, now I get it " But even if you say "no, this is absolutely wrong", you are given the opportunity to interact with us and other readers by discussing online the concepts presented in the book, watching videos on the topic that you are reading, and listening to commentary by the authors Each section of the book has a QR Code that brings you to the accompanying page of a companion website with space for comments, videos, and audio material to complement the content of the book. Together, with your contribution, we will shape the perfect future of information technology in a decentralized world. We are waiting for your comments Roberto and Barton
