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

2b2cea2cc86c3ccb08b42eb5a9be15b2d5a9f06e5da25e880887e2629d98fd41

Seed

479599827463f8b4b4030653cc181f93658536ad90f7f2af02a8d185096e3f0f SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

12247fbbde8ec17c0e306f5efbb3a37b

Commitment

Batch 48,215, Merkle root 86d3ca3c34ff752db9333a45188f3d39e8f5b722853307123dc0c346df94ea95. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. c8fd6e650e6388dbe6a96f4f358238cacf4fe8cd45455ef3bd7830301fbb99eb
2. 43842a1779f48865416b64f607fb51f50619bedbb8e78cc97be520de27c08ebe

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.