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

6736bfe3ff823b24e93605950166fbf9e87c86e8e9c09dcd0c9456693a66130f

Seed

2e2f00cba19cb87e52a49d01f23a7ce41bd679fcd13dc9523d6dd7316800a6fe SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

36e0b8c8452d20e6b6c21fa2727ed28b

Commitment

Batch 57,606, Merkle root 5468e1a491ab61357bf8d1dcaace2e3e14f62f0599f69c523e08b7f5c76737fd. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. aead5bfdd3e1fdc01241d7ae9a9c687bab78709009e3b5d2e34c330c3c5c8ee2
2. 26ff2e0348eb4028a24d69bec7bca2227266fe494f07fee547c46498690a9be5
3. 97bbf50a2c8f9d51e5547b7bc1edb08d96f9698d180df14e69ef9c7b56ef80d7

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.