This chapter introduced us to the important challenges and limitations of distributed systems, such as the Byzantine Generals' Problem and the CAP theorem. Then, we moved on to understand the one-way hash function and generating a hash chain and a Merkle tree. We realized how a blockchain is a giant Merkle tree and that the subtle difference between a bitcoin and an Ethereum blockchain lies in representing the leaf nodes of such a tree as a transaction or a state of execution, respectively. We took a deep dive into the bitcoin block structure to demystify mining as an incentivized brute force attack. Forking, on the other hand, signified a change of protocol on blockchain. Lastly, we identified the three types of blockchain generation as money, assets, and contracts, and we contemplated how blockchain is going through its reality check phase, as per Gartner's hype cycle.
In Chapter 2, Grokking Ethereum, we will have a gentle introduction to Ethereum as a platform, which has its own Turing complete programming language and has the ability to deploy smart contracts in a decentralized manner.