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

9812ad9f18ad39adb1b17cf92b78bab31a1eac3a92cf586ebd4d926f4d834056

Seed

66f92aa14ac9cb5da228d0ea42b64d918d9d469447108a1421141b5739344341 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

656a0d1f4531aa1af78b888e4b592d9c

Commitment

Batch 54,727, Merkle root 38619a502d9f3cb02606c710ad77a04a6ed0316c205175734af6294bdc767def. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 6447421aaf2fd2907b6600af2307f99e1909f79304b633dd6cfaa5605dd14e2c
2. 01bd1f1fb2ff4beedb393986ed6aaa474422b2a12e50af25a515701f4c4947dc
3. 3c065ba2924c63ff463d7463b6a756270fa54c04d7959097fb8845bc172d3b66

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.