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

94260527cec887ef935543e5a5522faf35a2de3057e8017e43cb9f52ab29523a

Seed

31eeba0d4964000b9bdf89dd84d9676a0ac5f8a976e6e85ab3c4453cb0d19a33 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

e217a5c056e1d92f30b4379e5907922f

Commitment

Batch 70,134, Merkle root c60164a20638917b717c6533380d51bdce8cb836116bb196ad5648d1f951013a. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. 3755a07336c8c5decba9b670e1e1d117f9d6308b66c03f33529adff91bb83065
2. 583a3370c5eb05b2d9aa32429d8d9c87eb9daa7a38247842ad59f99c9456cdd2

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.