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

c3aaf98b3040d768e81a015b317935185ccffdf7a6a23be4dfbe59cffce152e6

Seed

e4a1437c90930aabb54717bfe8a2f858686adab258f569d9cda1118253ed799c SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

d8fc8e7919a47215d6c7bc6d9016c554

Commitment

Batch 68,989, Merkle root 9adae83d4c57846a9bc4fb99bb292f9c4cef6f0b5f8ad7d5d50b4c6f8177fa32. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. 9ffbac197ac9c65d3b8d1110d1149b6eb7b06bce13ef8b82f53ff8b619be68cd
2. 9e6f84434854d23a97a1853b708f414081fa834a547c4b4321e13e5fe6814f3b
3. 48e962dab9d293ca8b9c99f7e06a761a17a9c39143b96123c12a96e017cc198d

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.