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

e8f7566079546636a6f2c35476a65231e85ac33d38741d60d09d87f75747e11b

Seed

2ff21e5688d13cd71f8db1ac19bdcb372bc6b2e856cc905c4ca932c45c250dc4 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

765e117430063221d193be46ae79154c

Commitment

Batch 59,454, Merkle root 0f267cac0001ae8b19c4920c8f334d3f0d612918bcff3e1e1ab4578c9c5b60cf. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 10d18db82091f90d1df9c5df245820bfad356be1a61a3be386014b7222b0ec4e

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.