The Why of Blockchain

Abstract

This chapter starts at the foundation—the problem blockchain is actually built to solve. Before any protocol detail makes sense, you need to understand why trust breaks down across a network of strangers, why decades of serious attempts at digital cash kept failing at the same point, and how Bitcoin’s combination of proof-of-work and a longest-chain rule finally closed the gap. The Byzantine Generals Problem is not a historical footnote here; it is the precise shape of the consensus challenge that every distributed ledger must answer. By the end of this chapter, you will have covered: