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

05941fc284e3c1ed2932c1bf529e69e7b216debd5187e148122ca2db44bed849

Seed

5fddaa731630013aba06457528631266071f92841ad3aa98af496e2bf27e6f41 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

10716e192dce699885bdba7d5e27963a

Commitment

Batch 68,480, Merkle root 55020f8bdf2cc03328a77e1bfcc90d94e6bc8eb36a19530ecfd20e0b012c6050. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. bd9984292d2bee6dccfce1ccdc386b24368074d4260ac8eb7fa42a9641836560
2. c566e709ea48440e160e4e1e926a1a76e7a024cc118077f00730d5a95ef24c31

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.