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

7b50ccdca380717799416606fff6ecc09823e8060915a9087156dda85f5b3352

Seed

a96ccf02eaff86679d2c20ebbc4283c24b9a68ab972305094a9645c832e3e5f6 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

d245dc77bffd2c5efc25ca4035a8d314

Commitment

Batch 66,907, Merkle root 262db394c1ff683fb4daf6821a45fba9221a9eb8c221dbe2788ef8b8c3f4f27c. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. 65f1f6dd1f011cfe05c3094ea63cff6dc78c5291e98a0c6b126b5b684d8cbefe
2. 88364a8297fcd982d1edbd37636b1e3a342dde393ea0e7cdd2f2bc780a769f1d
3. 09f5771cfb8b6f0efed5fe91acae5239c3d8c92a5e86e7c49851a0479ee18f7f

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.