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

f1f645d8a3f4ec06474fdbc6b77002cf08fb4eec31342eba5465c8edf847774f

Seed

ce239e38b3282627c019fac4dc6f7155ff0cd6f77bde9886589f525fb5a154b5 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

98012799e887a63bdac6dd2e5099b436

Commitment

Batch 47,701, Merkle root affc23607ddfba185e99466958b51a21143dcf65c2430f82d86fd40999110f33. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

Empty: this session is the only match in its batch, so its leaf is the root.

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.