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

af5c59a67b68a2b0a7f4f7dcf16d82a872396544eb6beb06638c72ae1451068a

Seed

4d41ebeeb3bb6071c81fba20b16953ed5a85a5e003d98841b7f9b58235742318 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

a39e6530dcd7dc38e2670a355e60e2f5

Commitment

Batch 52,793, Merkle root 638b097c1cb8b362b58a931e6541e45bf0359d70069f642fe79a03b339bda0d9. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 497a6403d2f5c32e854a19dda39ecaf2285e32a154640197b6839d87eb6ee30a
2. 7081cf07ca93b1fcbfb0ca7411eae834466154aa6d1e4e879cff17573683d995
3. 1d6d340a31682d78ac8aec640c6503979b8e53fd8969a13bf8072460ba32136f

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.