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

d0b556cac1b4ea16d0f1f2c3a4c948b3c87100a6c43a45d16fef3fae3b5d651c

Seed

ae655f0ae7c63980eee53b413c076825edbafbf5af73e5c07ad48e5a6cbaa234 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

4f340a918559b376051b90586bc156dd

Commitment

Batch 47,152, Merkle root 82cff24d35b413cc1c7ae1f83c36f6fd7366d11ebbb538c9bbc7ca4f6aa82aab. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 0e17143a9a1a135667af93fe811aec639fd5f35d14574183720bb034aa544753
2. dbfff86fffd13fae83db36a27e9dddfed3d4a9441470b20c6e2ffc82604ba0ad

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.