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

889cd2b8de078c20bc9056fa3078bdc7e25481cb92c685efbd16cab930f0dd15

Seed

778b4f330a391ffe1aa471078c987fdfceed3df68c5ccdfb588b14876eaaecfe SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

c090b449f9618d7bafcc9bcfcee3a8ed

Commitment

Batch 71,669, Merkle root 62807c965264d02d3673f364ecd6f0d81bf751e0c68d5c7f14988cc3fc1c531a. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. 71742955ee2da8578d938b8f96d4a4afcea9ab0d095d8ca5f843cfecd3282a9d
2. 5ec5f88cb0cdc63b55344067ee6e619d9259b88881f1905c38510ff4d8a277a1
3. 4a7a7165b50e01fc3ac5c2a5182594fb4adcba9eddd4c6145ba0a4cb35dc10f8

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.