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

6f68084f7d272061547ef116948dac801c5248cfc5fb924bfb74e2afe2dce39a

Seed

22d35b5496207cfbf8cf380ea25450fdfb65360d5888c718c64925b443c92cee SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

525001d0a46394d9a3d803ecee40a6df

Commitment

Batch 57,815, Merkle root 1897299ef44785bdbab7e3bee6b74ea9fb7b1f87982cb5f45a0181bbc9580385. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 8daa9e587662f0c2e4522a6f8f7ce9de36d7588a748208e4fec5b8c5fabb4a16
2. 200dd66fbe1d5968f9208926489d12105a257c56e4906c28e5a3c94507acb2fd

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.