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

c2c6a5eac137d6c9fc2bf50c8d3aee5dd0b725390c84bfff15cb227aaa967d58

Seed

1c6f240beafd210295b619d0e598affd60d94d333c6b0a186865ee3a7d9e2c1f SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

96394101a482d995795b4bf44c939e78

Commitment

Batch 53,071, Merkle root d6374f1fbdbce4a781f5654eda2124d15e9ddd7fa613862cab6de008c477554e. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. a8e56b8ed9be966b94b06b6de0cc4ad90c5e37a5a4bcb184a01d52c56cded4e9
2. 2def6150d74fdd4ed9069353f7cabe1c561e2cb081dde699269206893f5dc842
3. 971f1366f6b7ce517764a671d33a65bb665aed7c66d698530327d3ac836188d2

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.