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

e9f027c2bf7b134f3392b1bffa09266258743dc72176be1b36bf5312ae557a49

Seed

5dcc33866f85d389e580c8cb6e08ad84adb1693b89be432e84fea8a98965effd SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

828da0eae5ea89190d7d5883cce9a6c3

Commitment

Batch 65,273, Merkle root 868af9546e077be34d3734d576b39b56159d7b7124d9d87a0f83c4d2a2983ff4. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. c810ae0f7287fad417eb28f886879b835e99caa85c92ad9e795b248359bf6e06
2. 1612b3c44dabc0761c3b2db0b10939d324c6b6c2a128d87363f2ca1d051b2930
3. 4a92e1a410b4a7f0529f1734e0a837d2bc18480c894f0315dba30e4b62c0bd29

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.