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

0ac27862da7f9c6cb7ba878c0a6da9859fcb95dcc78e179e2e53a92dd146bc2e

Seed

6fe1ac58822bbb65416f6c844b8779d83e83d6b79ee7b7d7df05bdc946579693 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

785d44003fefe4af0f07f55ea1380cf2

Commitment

Batch 58,674, Merkle root 4910738cf79fbbb0a51b94947dacaec20721d329669c462fdf7766687c23bdef. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. e5e437cbddc5d83daf5887ca29b0bd4bce1449b4da49e3f5ba4ad3ec5ec51a6f
2. c1d30b8a7d5efc34a8154d489be16708dc96d8850e4375cb06c33810d86fdfa1
3. f1af72b5211b823335efcb6c0257f3e3e00b830171888b9858e68ab9053dd2ba

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.