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

392a2c8206430c7ebb2f9eff269b30ccd1f1c11e59b723735e32eec4fff61d61

Seed

1b320149a8d3c3997716517f545960642c8908325a471eff2a20d66b53ab1910 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

265ebd2f1a21752205ef1162beef4a3d

Commitment

Batch 51,479, Merkle root 4e81ca53659634124791c00bffd0dca4cbb2557da2723bd3da2ab3fae6c2bd7b. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 3b523ecb8ead3b5fdf5c4f0aa0a31c1ac6b5c416aefc672770d62aeaa6b8e4bf
2. d75f7592479719fbfaa57d63776d134090fcec9da6b0dd702135b1387eaaab5b
3. 6dbd1bbe83b76270bbcf7e255bfd9468bc0f65b63292a6387338e0410e634e6b

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.