03 · The N engine

Normative source: N-SPEC v0.7 §1.1, §1.4, §5.3, §5.4, §7.1, §9.3, §9.5, §12.1, §12.15, §18; WHY-N §2, §3, §4. This page explains; it does not restate rules or parameter values.

Valid operations can belong to incompatible histories. N answers which history to follow. It does not make an invalid operation valid or replace the application's conservation obligations. This distinction separates validation from chain selection. N-SPEC v0.7 §1.1, §9.5; WHY-N §3

Production without voting

One producer per slot, drawn from burned tickets with a Bitcoin-derived seed. No committee, no quorum, no vote, no finality gadget. A registered identity's active tickets determine its weight in the draw. Selection identifies the producer for that slot; an absent producer has no replacement. WHY-N §2; N-SPEC v0.7 §5.3, §5.4, §7.1

Slots belong to epochs. The epoch registry and seed determine the production schedule mechanically. The seed uses Bitcoin and the registry; block content and producer signatures do not enter it. N-SPEC v0.7 §5.1, §5.4

Validation before selection

A signature does not excuse a broken rule. Nodes validate candidate histories before applying selection and local adoption rules. Historical validity and local permission to adopt a branch are distinct: a node can refuse adoption without declaring that branch historically invalid. N-SPEC v0.7 §1.1, §9.5

The score counts valid production blocks since genesis. At equal score, a public tie-break independent of block content ranks the competing histories. A signature, checkpoint or arrival order adds no preference. N selects a chain; it does not merge blocks from incompatible histories. N-SPEC v0.7 §9.3, §1.4, invariant 17

Bitcoin supplies context, not an instruction to switch

Bitcoin supplies roots, verified facts, time and randomness. Each N block designates a Bitcoin reference; Bitcoin reorganisations have their own handling in N. N-SPEC v0.7, preamble, §5.4, §8.4, §11

Bitcoin fingerprints can trigger STOP. They never promote a branch. The H1 detector can leave the base decision unchanged, delay it or halt it. It cannot change a chain's score or select a replacement. N-SPEC v0.7 §12.1

Origins and limits

A new node, or a returning node that left the reception assumptions, needs a recent authenticated origin to enter the registry agreement domain. A node with a local origin does not replace it merely by receiving a bootstrap package. Exceptional recovery requires explicit acceptance. N-SPEC v0.7 §12.12, §12.14, §12.15

The quantitative claims depend on the published domain H_N. Outside it, N makes no quantitative claim. H1 is not complete long-range protection, and a deep halt can persist while a conflict remains. Read the limits and published counterexamples. N-SPEC v0.7 §17.6

See also

Producers and tickets, Depth and statuses, Where trust lives, and Glossary.