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

96aeec149c14dfc67282a8db9f3b78c9488a6a48ac24c23683df4fe9ed838a3a

Seed

549e4f3e4744e735fb7ecf7ab9b689857dd57bd058a94552e1fcda6a1b60afbc SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

6d58d1048f59224619cb40d2e4e452ac

Commitment

Batch 71,252, Merkle root 61707978abfff9e559388f765b4ae8ffa37b6aa28a063bbdba8922dce4bc8a73. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. 16cc3b80d902bb0e6221f9d43888979457132d00e569feb0f4a16799b27ee302
2. d1ee14f6c99be5c173c53ced985024a354bf4c9752cb3b8cf39daaec9754b5c1

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.