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

1a6a951a2fc656e59cbf6f778eebbc33a2ef89bd40ae7077f3ee39ae0ede1d14

Seed

fe8f473ccbb3f09510fb00128220e044712b1aa7bc333791cc322584e635e6ca SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

018137cbd14edefd48647091ee8d325d

Commitment

Batch 73,154, Merkle root f03772c7f6f031a43a50fb54cf812b42092762532f3c897e20a9b0f895f1061e. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. bb044dfc6969bc50733a932976a1452e07d0a88bc64ec2ab4c553d9335799aa0
2. b3902c135ec6608b6f7ab8db01f13534b151c2c71c6b3c793a8df5290eaca9a8

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.