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

caaad7b5c7d5e9267d099c3f91eb14c0da8fb8727991b7cc58be0a38f8e12bbd

Seed

68e0feeb43a24de9f5868378d63dfb3946dae7399976f733db303baa0ccce363 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

6dd17ff4b42e9c19ecd1cb1c624c3bfd

Commitment

Batch 47,972, Merkle root a3fcc7a7ca575e2c8fe7e246c1e600e60e0af93bec1a94835d8bc2d79ac5fb51. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 1e944c884ce7d161ec065e5cb363b499f039cc97dcab0fe5f2e880af75dca69f

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.