Reading library

Re-read Day 1's "Read deeper" recommendations if you haven't.

Notes

Specifically Matt Levine's *Crypto Story*. If you don't have time for all 40,000 words this weekend, read sections 1-3. They are the most important. Levine's framing of "what crypto is for, and what it isn't" is the single best lens for everything we'll be doing in Weeks 2 through 4.

Related in the library

← Back to the module that introduced thisModule 7 — Part 1 recap — what you actually know now

Crypto Glossary

Bitcoin
The first cryptocurrency, launched in January 2009 by an anonymous developer or group using the name Satoshi Nakamoto. Designed as peer-to-peer electronic cash that doesn't require a financial intermediary.
Cryptocurrency
A form of digital money that uses cryptography to secure transactions and is recorded on a blockchain rather than in the books of a central institution.
Blockchain
A shared, append-only ledger maintained by a distributed network of computers rather than by a single authority.
Cryptography
The mathematical techniques used to secure information. In crypto, primarily public-key cryptography (which lets users prove ownership without revealing secrets) and hashing (which fingerprints data).
Decentralization
The property of a system in which no single party can unilaterally change the rules or block participation.
Double-spend problem
The challenge of preventing someone from spending the same unit of digital money twice. Solved by Bitcoin without needing a central authority.
Block
A bundle of transactions added to the blockchain at one time. New blocks are produced on a regular cadence (about every 10 minutes for Bitcoin, about every 12 seconds for Ethereum).
Hash
A cryptographic fingerprint of a piece of data. If the data changes at all, the hash changes completely. Used to chain blocks together and detect tampering.
Proof-of-work
The mechanism by which Bitcoin participants compete to add the next block. Requires real computational effort, which makes attacks expensive.
Node
A participant in the blockchain network. Full nodes hold a complete copy of the chain's history and help validate new blocks.
Byzantine Generals problem
A 1982 computer-science problem describing the difficulty of getting independent parties to agree on a shared state when some of them may be dishonest. Bitcoin's blockchain solves a real-world version of this problem.
Block explorer
A website that lets you read the blockchain. Etherscan, mempool.space, and similar tools show every transaction, address, and block in human-readable form.