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

0ebd9173b5f79ed3310d266472d02e95f1e04c2bdc4253dcf41bf400f17adee3

Seed

61ee9f8b7407b0d53e2cdc8fe8e83ebfee819cfbdbab405946f864d2d38c60ae SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

70976ee976eae084b826af92e1edc4c2

Commitment

Batch 58,184, Merkle root fb96a44669911326da8b62b9e1880a9a147b7379524a7af1f68be2858f6d9661. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. edfdb9cf1df4d3ce636249009fff109e4badae13e1e422ae9aff8374f43ff04a
2. 2929e4b4ce2c9bbd1346a2d486e690ec1782424a9187dd1332f6932989140115

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.