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

da8746097f595f6a72a3c0d8575ab5a80bd6c160a84d8e205e3da97406979d28

Seed

a95b49fdf0b48a82e279200d0bcc3e699dda2aea6a24d406fe9be3d993e4313f SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

1c4cb1edfed8d6de8f5b309296c12a21

Commitment

Batch 70,290, Merkle root e60a52dacf3aabbb774d4a8221ac825954ba1866533b4d9626132127b6755718. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. 01cb89abd60cdf4368d4eab942cac0f70c4c21e92f31052368950d078ee08602
2. b5713459531807534e71d9c016a3b43837ed6499db0d0455ee0ff912312fd4ca

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.