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

58d769c40a870abe4b5f294fe8c6ffb4f1c7c56c76289ff1bdd5ba8351ac0065

Seed

bbf32ad47ae6bf8ca7688525276f0e840e397fbe72be17b7ad5d65bcb9bb0d6a SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

d01a4bcbf8c0a99c8631bc0a0dc77148

Commitment

Batch 50,235, Merkle root c306ba800a1e4c82cbeb5a962b7099048df89ad894d394fbfedcd26953f368f8. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 12067b080e9300d9b30326aca62703b5be03d885e8edb6e121dc132088144a84
2. c5c936bd62a5f20bc3fccdc4efaa9659ad97255dc36218d9ec59ffe61e8411bd
3. 7eedf4e2bfa9dc3f6d45a18849e2150c941aa8865cb77cf1e7d494d375e86962

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.