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

a6dd7f495f87aa0583dbd1c9ae966cedab310aa9129701207b894bf32ba4fb9f

Seed

540ce727566e83f3ded712ecbe8e2c026c65b79c2f85e8178e615e5b4ec33ba7 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

ea81c97a83c08757b78c891866033712

Commitment

Batch 54,167, Merkle root 68e64aebe891560d3f411a86a86d13502bcebbc495c515e570cf9301385e6c0a. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 774baa3ec9eab2458b7eace404d50c88a314d284f7df500a6c16f25891a9c175

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.