Blockchain & Bitcoin: From Hashes to Nakamoto Consensus, Build a Chain Yourself

Bitcoin's most counterintuitive feat: a crowd of mutually distrusting strangers, any of
whom could cheat, nonetheless agree on "who owns what" — with no bank, no central server.
This flagship build-it-yourself course takes that machine apart layer by layer and has you
rebuild it by hand: no mainnet connection, no heavy libraries — just Python's built-in
hashlib and numpy, running every piece offline and deterministically in your own sandbox.
You'll build a tamper-evident chain from hash pointers and watch one flipped byte cascade
through every downstream hash; write a Merkle tree's membership proof and feel why O(log n)
suffices; hand-roll a toy elliptic curve to sign and verify, grasping "public key as
identity"; walk GoofyCoin straight into the double-spend problem and see how ScroogeCoin
fixes it with centralization — and why centralization is unacceptable. Then the core:
Nakamoto consensus's longest-chain rule, proof-of-work's nonce search (finding leading
zeros), and the attacker-catch-up probability from Section 11 of the whitepaper, which
you implement yourself — dragging attacker hash-fraction q and confirmations z to watch the
double-spend success probability decay exponentially. Beyond that: UTXO transactions and a
Bitcoin Script stack machine, difficulty adjustment, mining pools and the 51% attack, hot/
cold wallet storage, on-chain anonymity and mixing, all the way to altcoins, proof-of-stake,
and smart contracts. The course follows Princeton's Bitcoin and Cryptocurrency Technologies
skeleton plus Nakamoto's whitepaper; every session is original hands-on teaching rebuilt for
the online sandbox — typeset formulas, diagrammed structures, draggable parameters, code
that really runs. You leave no longer treating a blockchain as a black box, but knowing why
every byte is where it is.