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

cee9c626a610738120d589084e1965f6d18f6f5cec7d9e8be349ea6d801781f4

Seed

0700371407ac62b924dbc081ca5d4751685fd6a309718fd842be24b2265cdc5d SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

3b1f83f59ef3e585261848409e03ccbd

Commitment

Batch 56,222, Merkle root 08362d9054352f23e963d3195af0e4863f24309a7d521cfb7467ac7b1033a4fd. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 3a62891501da5f1816279b8a2ab83fa725462c581a538b240415dc4a778838f9

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.