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

daaf61373eddbe3677f7532995dd7b18b24661ba1d06bb97a4d61d80067c4b90

Seed

28de220fb12bee9a49a72a1a4c673f113ea50f0416d6f74214d42666ce316f91 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

d57f18e0c0a38f2f63726e42383d0595

Commitment

Batch 59,185, Merkle root 5070ff9a520d8295910fb3f3394f43b7cea86a576d08507c92abc45ffd4f39b2. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 4968f3d36b415e8cdf6d8cbaa486964a695fc2ab66d2b2c63f7b2c6e046d7ec9

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.