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

08d6ae001b33a8ab74c1a87426c6c441848099ad887865c9219751226a71e709

Seed

4bf9c7c1927f6b55ee5b8c0a7fa189fcf76f6bbd23429132cf7cc0fadac6cfc3 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

78444222ae35680c31e5633240acbde4

Commitment

Batch 52,253, Merkle root 6b4ff813d587e53cf400aa1f780a460e835a9739e9f2521394f21a33584f5d87. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 28c73275cf87577178df29997b621a670c5f7d7aadbeb5da3d81d7bd95952149
2. 9dbefe950999424b9e66a0c8282a5ebe03a0f2f28271f8b3362b455280f36059

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.