Merkle tree

Peter Todd announces OpenTimestamps

Peter Todd announced OpenTimestamps, an open-source infrastructure using the Bitcoin blockchain to timestamp unlimited documents per transaction via Merkle tree aggregation.

Bitcoin architecture evolution — Satoshi era v0.1 vs modern v27+ baseline

Cross-cutting architecture comparison across every subsystem: Satoshi's v0.1 (January 2009) side by side with modern Bitcoin Core v27+, with split diagrams and domain tables.

Bitcoin consensus design — proof of work, difficulty adjustment, and fork handling

How Bitcoin nodes agree on a single chain: SHA-256d proof of work, the difficulty adjustment algorithm, block validation rules, fork resolution, and probabilistic finality.

Bitcoin cryptography design — keys, signatures, hashes, and address derivation

How Bitcoin uses elliptic-curve keys, digital signatures, hash functions, and deterministic derivation to secure ownership without trusted third parties.

Bitcoin transaction design — UTXO model, Script, and signature schemes

Deep-dive into Bitcoin's transaction layer: UTXO lifecycle, transaction structure, Script evaluation, ECDSA and Schnorr signatures, SegWit, and Taproot.

Bitcoin system design overview — architecture, data flow, and design-document index

High-level system overview of Bitcoin's architecture, layer model, and data flow. Entry point to a 12-page design-document series covering every major subsystem.

Bitcoin security model — attack surfaces, trust assumptions, and defense layers

Bitcoin's threat model mapped end-to-end: what the protocol trusts, what it defends against, how each attack is countered, and where open risks remain.