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

5811b6f1bb5efa4113d361af0085a77fd83068e1245daef25143b10450d83824

Seed

796dcfb19b96212fab3990e46437a51c2b00a2e025505ed6c1a16ba5e93ec1fb SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

10cc573e518f097963d1f259bcdef32b

Commitment

Batch 54,968, Merkle root df5b82e859b465931fd3fec967ee4ab65e9a997d4e798d5898e6e33f80dd7645. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. ab40d5fbf4c60ac1591db3a4f4f0cb625fc4534ff2e72f353cd20ecd0ad6495b
2. 137be1d9624b45a16d2f8c20e5a5373e283992c4f2ba5099caeb5323788b0dcb
3. 0bb532bcd5c95512f72f3f79c94c94c4587fc2e95a00911b87d1c28516867805

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.