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

149462ae98f1f8b0f98696ede3b6c983ee4ff76c85be23a1bb7a40d1b6c6c98f

Seed

ae7c2ccf2ba6800b95989f4780ec26281c2db25d0c7a31fae6e720d5c430b50e SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

7c6d7461d01299e6d9b8aebd1372a805

Commitment

Batch 71,014, Merkle root 1a1720f3525a4316619c475eaed1c1149bb7039c36fef0613e283e4b8633a947. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. efbe29d16b0b04e8f771a05142d7df526403d78edfc88de3289f7f8a238e1d2a
2. 1cbc22f14507f9a570d981b9641586b4595cd864e831cf8130030c4fbdee475f
3. b02b862a0a0f8c50bea7c686cf5194b607bbc62e5b772b5fdb0476b8b930a864

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.