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

c96b53c580bd822053412852dce1c9833ef818fe57982b2e39ea43c3ddf0e0fe

Seed

fd2ade46616f7e4b42d604850936a3dce78f62a6ee47e93ffebd16bb5b29a0a1 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

f98f35a5d75c3702dc00eaf11b22fc86

Commitment

Batch 55,934, Merkle root 786bc9d8a0cddb7e624540b1f040d6195e68f5f4e94e27faadf291131da6d6c3. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. c3491bef08eae6cf8ec26307fd5329a8dff54a3198c320e311600eb4c27781e3
2. 2eb4767ae182c5547bb53c333d5cc728804d4982a94d487868cc73901d066524
3. 6c5861d064ec063eeb299fd5122e7725132ae1023b146fae4268940d97c15f06

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.