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

652c993df3f0d361c0b9f3fd1b5f6a90621d7ecbca2263bc7cb20e3cf0dc6b3d

Seed

0a6703c1ebc0ad9fbc0abfd74c5623f9e7d54bc849d1800a7c968276e595a823 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

aaaed132faa4c272da5b949a43f97e39

Commitment

Batch 69,629, Merkle root 5bb0aa964741719022d265afa29bfdd45219a8115284b71b2c5539d9b37afdde. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. e2a6ddf82687bf1c30b57c4318a4cc665a6e5adf98f8f994131dafd5427abbfd
2. 22df3f8bc5f3ae538eefdd23e85c52fbcbf3fc4dbb6e21d15ac1e5e4d432b0d0
3. dfaeed24fdf670a626b7efc8c10b9447b123e34cb4ff0dfaa06373a104b51155

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.