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

d114441f4260c5fa14cabbdf725f05ab237fb49d417fd626ca18529776217d22

Seed

3d2115efeee041b12f1de818adb0a3e097bb8bee4e43d16e868a9160ec65a64f SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

239813298546e8cde215d3aaafdcd0c4

Commitment

Batch 65,423, Merkle root e81ef57cc41cd7f2bede7001b15bed62bcf9883bd1b64fbc18d40ea47457e656. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. 207f769e1ce3fdab0512b3e1387baf72d02527b9ee284edbd1c6b6d6219f67b1
2. 3a3ba9adb393dd3eecc2e4e14a46c3619f861ab6178564a621dc532a44382ca4
3. b07dac6f0c5066453053e53cb2fb36a467aee1e8fa1e30030be2a6b74a4d5c38

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.