Blockchain Fundamentals: Cryptocurrencies and Ledgers (DLTs)

Explore the fundamentals of cryptocurrencies, blockchain, and ledgers, and learn how digital money secures transactions, with hands-on critique of a strawman currency and a class discussion on privacy.

Explore how to create a simple digital coin by building a fully functional cryptocurrency, starting from a gift coin and addressing ledger security and privacy issues.

Explore version 1 of Magic Coin, focusing on security improvements via a social book balances system and login transfers, while noting privacy and password weaknesses and manipulation risks.

Explore sign coin, a cryptocurrency that uses digital signatures, public keys, and private keys for secure asset transfers and privacy, while addressing potential history rewriting risks.

Explore how ChainCoin uses regular block publishing and a chained record of transactions to create a transparent, secure system state and reduce centralization risks in blockchain technology.

Learn how a blockchain publishes blocks containing transactions at intervals and cryptographically links them to form a ledger resistant to tampering through decentralization and multi-entity participation.

Explore how blockchain ensures immutability of recorded transactions, global accessibility, rule-based rights, and strict chronological ordering.

Learn to build a secure cryptocurrency by using a blockchain, digital signatures, and public/private keys to verify transactions, read balances, and ensure tamper-proof, immutable ledgers.

Explore how bitcoin uses pseudonymity via keygen-generated private (32-byte) and public (65-byte) key pairs and 34-character addresses with built-in error detection, enabling many addresses per transaction, though not foolproof.

Explore how bitcoin records assets on the blockchain with unspent transaction outputs (utxos), including satoshis, and how private keys authorize spending.

Explain how bitcoin transactions use unspent outputs to create new utxos, allocate change, and pay miner fees, with Alice sending six BTC to Bob showing 0.95 change and 0.05 fee.

Bitcoin wallets securely manage private keys and digital signatures, generate user addresses from public keys, and oversee utxos to simplify sending and receiving BTC via barcode or text addresses.

Explain that Bitcoin is pseudonymous, not truly anonymous, as transactions are recorded on the blockchain, forming a graph of addresses that can deanonymize users even with one address per transaction.

Explore protecting crypto assets beyond digital signatures by backing up a seed phrase, using hardware wallets, and applying multi-signature schemes; learn to securely set up wallets and safeguard private keys.

Explore how blockchain extends beyond cryptocurrency through timestamping to verify a document's origin before a deadline by embedding a hash in a transaction signed with a private key, proving authorship.

Blockchains enable exclusive ownership of names through a globally readable ledger, and the Ethereum name service uses smart contracts to register human readable names linked to addresses.

Learn how crypto tokens on the Ethereum blockchain, especially ERC-20 tokens, function as application-specific currencies or blockchain shares, secured by private keys and traded on exchanges.

Explore how land registries migrate to blockchains, with private networks time-stamping land records to secure property rights, reduce costs, and enable real estate transactions worldwide.