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

f8054bc1896f37f23fbe777dc8551bfd5345759ec10e833e28604412976ad6ba

Seed

3eae54205b29fb1e3b8bf7624364c78566a852101e705807c25650d5fe662b1f SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

8a7f29b2e7864968f022611aea31b7b7

Commitment

Batch 53,968, Merkle root 184fea3e0516de706fd5a6a087beb4435f24639f173c4cbf4b9b9ad97da144ce. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 8a63d6f4f906ef05f8a7e1e1f59cd004e6e2bdf5e8bf6363c0440b4502b6d46e
2. 622b1bc14eb0b3bdeff11900f5820bca81d09fc2cea7083fe60e53c6c205f35b
3. 6ba1584296d56a3851f06571701029bea23af14ae71a62a60290f30bbf28ee21

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.