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

2cd675720e588db6e374829ee2c842d68ac4267c2eceac9fe848559d1098d310

Seed

1a4c1ef3b9fe4e2bdca51330f80c7685411667b7e3d23c1ae86a3676e88602fc SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

930e12da543601406dfad4d5de92b112

Commitment

Batch 48,334, Merkle root b2a1070f88b9f8ce4fb34db1241c7ecc961f2b8f44cf11416b017a2e54eb453b. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 1830f14d79c0c9e8c086065c31356b732207583e13eac9c3b3e6936120cf5552

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.