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

626f639cff95abdd89a863f21ec690d31b0cd1095d75ce6f48fa456f7a0ccef5

Seed

3c79dec2771f8108dc050dd69d0e2c9dc3ef5be99b5ee8a5b90628ab37721e79 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

8ce5c5b5ce384343b03dce0c879da0ae

Commitment

Batch 52,108, Merkle root 5c47d12b47fa664081be2c52d9022d3c1a9a3a1ca0e8db81e4b5af14d930e133. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 3c3b99d07fc72f3bb6783a4bd40beb8dd35d2816c48c15f790bf1990978ef4c9
2. 2a2320b6aed9565c63299bfb914f60e0c7921b1645340ac9d0799fa8e9d1ee07
3. c909955ff9414b807407ed7b90c856065fd50ec52e0ba78e45368379626dc144

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.