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

aed6cf02f623d97833e461300a307dacfbe6ae6cd3d038b4c03cebc8cd097887

Seed

56f7392bb527b91cd2af73983319c0864cf3482c23bfd3a746760e561604334f SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

85d0204c3436f448ed904ea5da0dff0b

Commitment

Batch 59,104, Merkle root 80430b0fff4d74c025959ff4ca28be14b0ee16eaaadc5e91a8e85bb694717303. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 5670244b1505e5b27bb7244bfab337ea2e9322a733338f2ac2afb33fc41b8ffa
2. 34c492ad4685953161d1f789874f0e1123303069627281cf49cfa08bed0255a1
3. 8c5203d0fa36aef6f9bc481e916bdd7b48b4acc4120e297ed4d5a101d422630a
4. 635034bf0ff271729e13b8badd53cf3d5344a826ed6dbb908d97312afb8bb2c3

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.