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

268e7acf96b2223ad26bf08df110d64fa725cfdc68c288f6ea22c85052701544

Seed

6a7a2f061e91621d5574ae4ec910ff8ea7d95d8fca4409759a542d842576f47f SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

e9b7297c0c20b782c2828dffb717730b

Commitment

Batch 71,932, Merkle root 459273223828297ed32fcf50fd33f5f38326d1478e13880fb8c2d53d718602d1. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. 21543c7e7bd80d62bd2eff11d889f1184bbc3c7e0b0f2a100a09b84f63bb0590
2. 9131bc977266508f55608f8d5982a8ec9ab0667ce795b61818427477102ee6fc

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.