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

f45d24f95a0582f8479c4e96558759f6bad8a0a82410acc9709c36e557fae193

Seed

9e3c6e90b99d9c7fe35df79888ab3cfbd9be8b2776b1a7885e16cb6411b5c3b2 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

1db6f0f6b6f64adb37a1dc444761f2fe

Commitment

Batch 56,171, Merkle root aef76c4757aff234277a7202148180d25d92489f93176601491fb11aa9926c38. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 24d364d93ba9d0ef14ecf8e3363e810edb830d739e851aa4b97d6e86cfc8690e
2. 024ea0d141d5765e751a6049f9f7a9bf9d72a565a08fce4035331e1278314362

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.