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

de12b6e1b98d68e1f46325aa655ad4d5484dddb42b47725c6a1f7a2ad6f25f83

Seed

ab84380b0efcd2bf820bad945625ba56b182ae8b46b1f735c23ea7f910b5ae7e SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

7d2ada053e2811b3c39ca0ac03366872

Commitment

Batch 69,475, Merkle root fd46454568d24abbedb78eed115c5dc93cd9d6387959c7ab1d836e4c7ff4e8e6. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. c19ce6fdb8f77568bb8bb96bb3a123164dbc418954a019e77f76f3107b33d473
2. 6f5b504fd7d0618e3ba2d9e231d4c02ee700bb0f93dacbe8286e0e17be655ac1
3. ad6051bf1f8e43706ffd3af4a1ad80a405c3e328863e587442d6c4a30ad7d8b0

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.