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

47f1ebb725e24674670de91de1fa6c21cd170053931673274ebdd5968a2590b1

Seed

de5c2f2f5978cd939e8f9f324a05580e86769b223169d14f1373ac36fea73351 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

d1235f85746090601d718b2150248486

Commitment

Batch 47,241, Merkle root fc413e27fd92d19aee5c97dc4bd51cbeeb0d196c4fed9e8e7c1a0e80bd789f5f. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. f5c74c790e969f7c6d5c285ceb79a673773552534b798852e6ba23d5461d3671
2. 5f9f310f8e6d6d19dffb7231f7f0b0084022e5b4da4e731a787c6ab9e14d3184

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.