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

6d3e60e44b1d7d9ed281ad162be61d7686c264882d4688134291a46d06a325d4

Seed

3cf76b18ccb0df1f9232447a53a4b7fc0c3cf2ebd151c6a060751bc32f4c6637 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

da37a95a4ea5c3578c5befe38c000c47

Commitment

Batch 62,928, Merkle root 81b76dd55b32aede17d93dc15cc6ea948cda64c2a69ec4288ffb0cda63c5f5e5. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 23cf6ee6d149f841d37a4aa0bf96d65371418408caa4a3e77439b2c7383117d4
2. 45bedf46ac83706d627f91164e596c4369f2deefc2148f5b8d8c65a1b2bc3035

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.