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

ceb074c64dde607f9c1f62c1b7eb9e0c881d6cb1cd666e3901d3241642e530f0

Seed

73067de5ec093066e1a69ebc785583bcd2da73cd392c20e44fb15a20a303a431 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

798f5a2510c6258f52d3cac8d6e86901

Commitment

Batch 48,688, Merkle root f2674e84a3723b013bd87bc0828d46fac3030e1a104742e199cb6a5144a077db. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 9eeb386573a1a6e40099d93c04ab0d67615c09903545ab1584fa0488f6cc4986
2. 21b80b14adbc158ffe14fc568ceca088d226a82d7da182ac61b7d63aec329a5f

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.