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

131e5fb51c47d38231df38b1884686ffdf31e82deb28f090b9330249824ceb5a

Seed

4c9221b6f88b5f0a5e6d9076fd63585ea0df5f204239885978a013911ef4147f SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

17e729466cdacc24adbcda88dea657b5

Commitment

Batch 61,287, Merkle root 42c7e8fdac974a611a21aee79685deed9c82f7988724cc02f9a0cd8ba25745ef. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 1c237e28b90f336bf724a5ae76c9d2245fc2a261c067ca609d7d4bb0669d4447
2. f9a79bb410dfb0b5f3776c5dbc833ae4ebf62956ea29979cce5222fa74bab55d
3. 9622664c0dfbfb7b15a90f55a2e6431a1fd64317a560b67c4d8e3784e6f5455b

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.