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

bf1c3efbc22e2d44ac98fef721846da01dfdb99b6e0a97191e0febf64d6bc1f0

Seed

8114ca8834afb42c77dd09d1fc23c174e49bc805365c0e6e25a8149162daf6cb SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

76081fea8b6ca6d32b2cebc25ffdc707

Commitment

Batch 73,343, Merkle root b7dc1e91931d153b7a4e22fbb187fef881d1d5089332c3a8264879f3eefb4535. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. fb9b0186910c63dde1ba82c60fd03df700c983821cf07b97997a2688a29ebcb6
2. e1231157f27b57232b95de0b25a5d09b03a5c39637538c33b00ce697ceafa90e
3. 6297a875ea421a84a7db177bbbe3c55992d5bc8d7fff0e1c10b0baad0455a370

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.