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

c266bfefe023cd769f3890ff81b4adfa58cd3eda6d141bafaf30ba9c51eae251

Seed

595176d68ec0b60cb38a172b8598878d8a7f63de95ff3d4f448badb12e9a90ee SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

777a192665c017dd284ca3f529edf4de

Commitment

Batch 56,239, Merkle root 0ea83bddc9f71c050b223a3c720a223c21e503e7e9c098029d4679811ed771a9. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 3074b20bb4d301a1268d758430f5ce3220f013a13adfe7e79d3aa8549852599a

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.