Blackjack

Provably fair

Verify fairness

The session's seed decides every card. Its hash was committed before the first hand; the seed is revealed when the session ends. Each round's cards come from HMAC-SHA256 keyed by the seed over the round's number and the bettor's own seed.

Seed hash

3cf15930c9bcc871b680769c49355dcc5766eb618693a51aeeb84a4d47fea644

Seed

e069ec33429b7d3d986a1b0d37e723a0b34dabcfb28c54317b17b0c645eb6413 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

c87d8289f76629807d517d0ec8df097f

Commitment

Batch 55,992, Merkle root 3ed803d4e437019e8bf5a99b933b8d3ffd9d1b17787061df8a8bb067ab95a67d. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 845784297186f0bafa419f6e0ade42e967f5dffac8e5c78f60540f3b32762bb4
2. 948f1e8df29a104f6f74579af4ce62c8de6764abaee5dc3ce367bf7395f377f3
3. d86cf809f5ec13bd85c8540b9e658d88d92bd670c234a7e87825d92a64f0e6b0

Checked: the seed hash proves into the root.

To check it yourself, take the session's proof:

1. Hash the seed as above and compare it with the seed hash; prove the seed hash into the root with the Merkle path (keccak256, as for every match).
2. For each round: round seed = HMAC-SHA256(key = seed, "degen.house.round.v1" ‖ 0x00 ‖ u64be(length of the bettor's seed) ‖ bettor's seed ‖ u64be(round)).
3. Key ChaCha20 (RFC 8439, zero nonce) with the round seed and read little-endian 64-bit words; a card is the next word below 2⁶⁴ − 1 − ((2⁶⁴ − 1) mod 52), modulo 52.
4. Replay the round's actions with the game's rules: the cards and the payout must match.

The replay plays every hand rebuilt this way on the server from the same data, and marks any that does not rebuild as recorded.