Verify a rip
Paste any fairness receipt and this page recomputes the whole draw from it. No database, no account: the receipt alone proves the result.
Copy it from any revealed rip page, then paste the JSON here.
How the draw works
- 1
Commit
Before you pay, the server generates a secret 32-byte seed and shows you its SHA-256 hash. The hash pins the seed: any change afterward would not match.
- 2
Your seed
You add a client seed of your own. The server committed before seeing it, and you never see the server seed before the reveal, so neither side can steer the draw.
- 3
Roll
roll = HMAC-SHA256(key = serverSeed, message = clientSeed + ":" + nonce). The first 8 bytes are read as a 64-bit number and mapped onto 0 to 999,999 with rejection sampling, which makes the roll exactly uniform.
- 4
Card
The pack's published odds table (snapshotted into the receipt) is walked cumulatively by slot order; the roll lands in exactly one card's weight range.
Check the commit yourself from any terminal:
printf '%s' "$SERVER_SEED" | shasum -a 256