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

074064209b4f8ba407a16d5a84ac9b75a5d711828076e9e62c77b55ca47b53cf

Seed

bca0c62e4275ac17555fb824492771627aa09904a8f748a8e9fd4bbbf14bbb18 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

3ef756f58d8cf1c44b49e17bc5bbb758

Commitment

Batch 69,857, Merkle root d171ffae059813873a00526b76ac2439869cd90867e1d14364cd0c3f652e7543. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. 1e0f2f97bc8e51e0fba7aa9ffaa8f21fdf38d4e9124a79ec3d5faea2b30608a1
2. 77d925113101262604c3d1c13bdaa991a9d811140e18b773b7b542fadd38df57
3. 36a76d56a177a2ec830943184a749526f7f5d957f931d3d8743d3e70e408d3ef

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.