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

cfa9381795a0d2227f952d3f80642823b8145ffa25366b5d4992bb134a70daf6

Seed

572a0c324d02dd9ec06861044f306cf03dbb32a2428486bff4479d5e2806531b SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

ecd19ba1ea20ba9b832782c194e1b738

Commitment

Batch 65,933, Merkle root 315c3f0c06e4fdd276c4c8dd5cfbc0e0fd87f0707eaa6e0d8b6ccb7f2be97d49. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. 28f648393b58b9be85a385be877a2e71139b4dc336bb8f4ca78fe46c5f036c41
2. 257092820cea6c7adb238ef6ced765f66d0026a14e0c06b6b04874629b2ea01f

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.