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

958f4f58983e3e158253b059835101cd3b37bea58c9099e384966cfed17a41cc

Seed

5ca72b268c8928a2840acd5bc58b10808aeea41c04089b6b0b21420338a0b105 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

dd5acb73ec42ebe21c3324afe74aaa26

Commitment

Batch 65,309, Merkle root e2abbb7f539a4c00593f08782d0a0ca9ad7807d2deaad39859a84d4f89f8b237. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. 2d5d141c71e3ee745af8747063255d996695a6304fe3050ce3b54fe6057c5728
2. 4d8d02adbbd2d9dfe7af2335cd3e67dc7cb90337a0f9b7ba6e7b4bf1b3b44119
3. 945c83aa74064daef1fef43b934f459d5327168004058934a7239a64cb47d87f

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.