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

4d3a2e13cc0bbbe7a952f662fe8f936bb470b8d5c82b0c7ca7f5541baf0c735d

Seed

d12981dce1d4106bc068d70459b57e521ee606d20c897593a4461be1d46392b0 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

686b6defa001340fb965b1e202ba08e3

Commitment

Batch 72,211, Merkle root b4921b9e4276e5de249c1adf3cee0ff1beb356cd38aa677ff006dbb6620b438f. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. 6a7345255df5eadc2a7016255d6caad5c8036a27a9c21873bb60c85c4609f654
2. 1d4b5acb3262594290f6a9938e3b2c622ef90b8d511a717c518f0a6ccd5ae6c2

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.