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

1b44b262971637f6267f90ec194deba1f6769dd97d0b651dbdee6ab53d0c5c15

Seed

5b188fb0186febd2a233f4848f9fb245d3904eabccb6ca81075419c62e93f60b SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

970ea9a1b5db12495a44557f017e5ba1

Commitment

Batch 59,830, Merkle root 6fbaa1fbec91b0c8683175a7c6a96017a00fdfe99195d91aedbe28c6c27ec5fe. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. e08785cd13523d155bb3bcd5d32632db7271a48f6d9204969190dbe8d2515e02
2. e4b681b9d587ed99458ddb12b969a4588968f1fdf1be0dd39732b1e586f17b15

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.