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

70623cf4370a3e15b43e6fc3f7f240264e72181c50335735e27243d0de9da368

Seed

2dfa49863c533b115da64412b927ac4787232e8b7375cf9ee91539cf7e3a4287 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

3862f588e0519cc51220b7e7172e1222

Commitment

Batch 48,524, Merkle root 068615680b635db4c2d0e5f28d6cb6b58adda2beadcb3c08bcdb9277f7b71033. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

Empty: this session is the only match in its batch, so its leaf is the root.

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.