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

554a2fe0b5fa135ce6e128fa83db9e23d9184ab1302d574885f03b4d9f7238d3

Seed

099f0327ce339eebe726279ed6dd5a8d6b68cdbecf2375f55363aa3bd44bae31 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

149ca2fa1f8fade4221b63da9b7a82e5

Commitment

Batch 68,585, Merkle root 1ff9ecb4462cf637ff39b02790d8a51f23ef2f74d10017d4d4d59109aa5ef17d. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. ad25da7b6b80734d7202a8200ece67a995cf64cab5fc862565a9b9e5d48d0ddc
2. d2a8a1ff4a3cc38c9bd3ca4d70b8bf405bb40463502ab5789995b0094a2c4ff1
3. c907d9f70ae9a88e9853a7be7147af681daa55b1701987968a006ae8c9b42ea3

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.