RNG Test Vectors: Crash Minimal

Submission status: TBD. Vectors have not been generated yet. Run bun scripts/generate-test-vectors.ts crash-minimal before GLI-11 submission; the script must write byte-identical output on every run (enforced by tests/games/crash-minimal/rng-test-vectors.spec.ts once the vectors exist).

Fixed (serverSeed, clientSeed, nonce, houseEdge, maxMultiplier) → (crashMultiplier, u) triples for Crash Minimal. A cert lab, operator, or independent reviewer can recompute these locally and compare bit-for-bit. Drift from this table invalidates the conceptual RNG certification for this game.

The machine-readable form will live at ../fixtures/rng-test-vectors.json (co-located with the test harness, generated before cert submission). The canonical code under test is split across packages/rng-core/src/index.ts (shared primitives) and games/crash-minimal/src/outcome.ts (game-specific mapping). The vectors are regression-tested by tests/games/crash-minimal/rng-test-vectors.spec.ts (TBD) on every CI run.

Verification

import crypto from 'node:crypto';

function verifyCrash({ serverSeed, clientSeed, nonce, houseEdge, maxMultiplier }) {
  const hmac = crypto.createHmac('sha256', serverSeed)
    .update(`${clientSeed}:${nonce}`)
    .digest('hex');
  const bits52 = BigInt(`0x${hmac.slice(0, 13)}`);
  const max = 1n << 52n;
  const uRaw = Number(bits52) / Number(max);

  if (uRaw < houseEdge) return { crashMultiplier: 1.0, u: uRaw };

  const u = (uRaw - houseEdge) / (1 - houseEdge);
  const raw = Math.floor(100 / (1 - u)) / 100;
  const crashMultiplier = Math.min(Math.max(1.0, raw), maxMultiplier);
  return { crashMultiplier, u: uRaw };
}

Vectors

TBD, generate with scripts/generate-test-vectors.ts crash-minimal. The table below is a stub showing the expected shape.

#	serverSeed (hex)	clientSeed	nonce	houseEdge	maxMultiplier	→ crashMultiplier	u
1	0000…0000	client-seed-a	0	0.01	1000	TBD	TBD
2	0000…0000	client-seed-a	1	0.01	1000	TBD	TBD

Regenerating

bun scripts/generate-test-vectors.ts crash-minimal > games/crash-minimal/fixtures/rng-test-vectors.json

Rerunning this must produce byte-identical output. A diff indicates the RNG or mapping has changed and requires a CERT-ATTEST-CRASH_MINIMAL: line on the PR (enforced by the rng-change-gate CI job).