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

a5c9948aee276443cd054a8a63bb5a057022a9638ca55f1910c027b90554bc9f

Seed

24a955c41260359d1a6209b1c33c2ba6b97a95dc57a228c8ac34e966ef9d55d0 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

7306efe8082aa300425bc3d644731bb5

Commitment

Batch 49,886, Merkle root 4b9b656e934f28af3501869b57225242f534393751985aeb22900d4086dfd33e. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. b287307126e99f68622692b09fed8b63bc9b2547dca6ae174c51116e483766b6
2. 5591906bf353647a4ed058ed291fac1f108b8d0de8ec1666476b5bda80058fa0

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.