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

1c984ac4aa151c7e17c60b1bad263abca71c5500ba7bd74d7eef59ac9b47e02a

Seed

29844d4833918da5233f10ea7dc368954250861926f6db004ad76c58a788275e SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

90ff5269704a000fe5f696f82f14c4a1

Commitment

Batch 68,554, Merkle root 2c0394a2cd86dcc30bc6d049f51d68a2f116e9cd8c83fd92c97b9b68c90f8de1. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. f404709e58c54a8d3a839e085e1e438f6d8b783cedbb39581bd3f9478a86d340
2. ad5dc7d42dff0f32e985fd489ae893dba646a7e46ff497eaa3db2abe3be126a3
3. e336a4186c28f05a03fc1dd676256e79fe189fba907ace17a96b1cc5b43f985f

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.