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

bec4e16ca0dfd567a270dc8238dbe471387e1574cef9f89243afe81196cf64fd

Seed

50667a5d522f56ed3312ad62fa1c7bf3933012b76da4982d1f252d23aac41065 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

2396f879a21588ce0c8d2d7bdc2d53e7

Commitment

Batch 56,584, Merkle root 326bf6149e452c087ed0a53b2e4baf7cb791a6f184e79b0df36663ff73852b56. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 5d74b124c78c9bf34e1b1b191d3c9dfc24e83bcfd2bd40556e25de779a3740b0
2. ed4343b90a5210da2e43a311c7b117dadf864c72523d4e91a76340ac812a96e3

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.