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

c74a60b011d7b39e809ee8397503dfeb52d33b9c1742198d5ea9b1427107ab79

Seed

4866d34bb9ce535c64a5f7287428dbd31fad7924a512238ec6de85748c18605a SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

f049b4b0d3e5464c9eeef31be607328e

Commitment

Batch 50,584, Merkle root eb481ac85edbc560654d8fcea0309c4c9f9d586b5f5a5e8ee27bd36cecdf9e5f. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. d4dd8347ad4887e256dabfcfed511a3848544b0f84861a6328057ab9d8470593

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.