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

202f01feec86e487904d3193b009818f1472434505aba606fbc9f637bbfff045

Seed

63f583c8b5da6a5ad133eda4bcb8bb6fabc98f1e0e65d806adedab2bb29d4a24 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

68c2fbffd0b49d5ef11a51dfafbdea1a

Commitment

Batch 66,051, Merkle root 914a7b152fd027b96d6c5cfbd5a75eb9f92f512927da0f01c23df0b616766704. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. 21220521cea13c3faa49ae14b988f9bd724c360ed28e0796a8fb3ff0e8e84f17

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.