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

706ebf47da887061640644515a5c70dd473543014e37b24598b3006d924b6a7d

Seed

2b09fb803c4a00e80705cdd83a5bec3070843dc87b6777747f948251398617e4 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

9cf458691f6d590f0104d51d28d205e9

Commitment

Batch 53,148, Merkle root 0686a201270b62ec276091b2bed4fc97948ad7ee45fd6c32e2a718768ed4a9c8. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 75b0f5403fc4fcdf432eb07c587c76c1f2708e6c60c49859adeae924440f988b
2. 1cd569aba2116ef45116e7f4806d97de489367967e8040bb711a3cc34f582434
3. d4a84abf1e238bce213f34785ff617fb1f7bd2073e5be6223f454b3b8f4d64f0

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.