Technical foundations
Keys, transactions, blocks, consensus, and validation — how it actually works.
The cryptographic, transactional, and network-layer mechanics that make Bitcoin function. Cryptographic primitives are treated as black boxes whose properties (collision resistance, unforgeability, one-wayness) matter for sound-money and self-sovereignty; the internals (the mathematics of elliptic curves, the…
Cryptographic primitives
The foundational building blocks. Property-focused treatment: what each primitive guarantees, what it doesn't, and which Bitcoin uses depend on which properties
Asymmetric cryptography fundamentals; key generation; the secp256k1 elliptic curve as the specific basis Bitcoin uses; private-key/public-key/address relationship. The black-box treatment:…
Cryptographic hash function properties (preimage resistance, second-preimage resistance, collision resistance); where Bitcoin uses SHA-256 (hash of transactions, hash chain in Proof of…
Tree-of-hashes construction; the Merkle root in a block header; how SPV verification uses Merkle proofs; the role of Merkle structure in light-client architecture and in inclusion-proof…
ECDSA (the original signature scheme; secp256k1; signature malleability and BIP-66/BIP-146 fixes); Schnorr signatures (Taproot 2021; BIP-340/341/342; key aggregation and the multisig…
substantive engagement; see also light-touch in Public key cryptography and Signature schemes in Bitcoin
event-level engagement on which post-quantum scheme Bitcoin should adopt and when
Addresses and transactions
How primitives compose into the application-visible mechanism. The UTXO model is the load-bearing structural choice; everything else in transaction-layer Bitcoin descends from it
Address types across eras (P2PKH, P2SH, Bech32 SegWit v0, Bech32m Taproot v1); the derivation path from private key through public key to address; address-reuse properties and…
The UTXO (unspent transaction output) data model versus account-balance models; how transactions consume inputs and create outputs; how change works; the structural privacy and…
The stack-based scripting language; opcode taxonomy (push, control, stack manipulation, arithmetic, crypto); standard script templates; the deliberate Turing-incompleteness; how Tapscript…
Blocks and chain
How transactions compose into blocks, and how blocks compose into the chain
Block structure (header, transactions, Merkle root, nonce); the chain of block headers as the chain anchor; block weight versus block size after SegWit; the 1 MB / 4 MWU constraint and its…
How forks happen at the chain tip; longest-chain rule (more precisely, most-cumulative-work); reorganization depth distributions empirically; the confirmation-depth conventions for…
Consensus
How nodes agree on which chain is canonical. The substantive technical content behind the "Bitcoin's consensus mechanism" framing
Hash-based costly-signaling; the SHA-256 difficulty puzzle; why energy expenditure is the mechanism's load-bearing property; relationship to Hashcash (Adam Back, 1997) as the immediate…
The 2016-block (~2 weeks) retarget mechanism; the four-times-bounded adjustment cap; how difficulty tracks hashrate; the dynamics around halvings and hashrate shocks; the self-correcting…
The full set of rules every node enforces (block validity, transaction validity, signature validity, scriptverify, etc.); the rule set as the inviolable surface; how rule changes happen…
substantive engagement on what happens to mining incentives after block subsidies decline
substantive engagement on 51% attacks, selfish mining, and other theoretical attack vectors
Network and validation
How the system operates as a distributed network
Node discovery (DNS seeds, hardcoded seeds, address gossip); block and transaction propagation; the relay network and compact-block relay; eclipse attack surface and partition resistance
The three node-types and their tradeoffs; what each can verify; pruned-node disk savings; SPV (Simplified Payment Verification) trust assumptions; why running a full node matters for…
Protocol upgrades
How the protocol changes (or doesn't) over time
The two upgrade modes; backward-compatibility properties; activation mechanisms (BIP9 versionbits, BIP8 with UASF, BIP148-style user activation); the recent history of soft-fork activations…
substantive engagement on why protocol changes are structurally difficult and what that costs
event-level engagement on whether covenants should be reintroduced
event-level engagement on sidechain peg mechanisms
event-level engagement on data-on-chain disputes