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

e478d6642d6a54f90f5e3d9269382ad53b0016948e4861979fa2e1ff29142761

Seed

e24c5fa420308f619f973cf42796477fa7d5255cbbdce8e17aab7011912b0e5c SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

66ed9b0a8034bb43f87bf9516dea89a0

Commitment

Batch 53,535, Merkle root f762bffeb0943e30337c2e2c21e3b111c85557c484892f90fdc74454a43e3d05. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 0f1782841e6d7d0f340a9b2ceeaee21aaa644fcdaeaeedbc04c58b5c730d53fe
2. b043ee302aa42539de122d4dc4c50e5f72f280ec51bf3155bbdab64f1bbb2613
3. 329feaf4138152c1f8c69eaa252b86d23be45165a61000792baec21964533107

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.