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

6e9ce63af621b78ffc6ad39e060e5e5939acb948714c4b903db0ec36eaf1114d

Seed

95e6365dc4930666db53defcf829884af141cc9a2ced81d67090e2e18342ce40 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

673076759ec445370b5a8f7e039c1285

Commitment

Batch 47,867, Merkle root 837e7ce7c37490598f3de6b48aba7244fe7c2b43a476fdfac87975f99b06fd7f. Recorded by Degen Protocol, not on a chain. See this batch and its Merkle tree

Merkle path

1. 5d119c6bf139cb59641a0d7410801bcc5af7b643917636dfb3c669fd03f152e1
2. 6024d950a9bc71e6b7726c5d39ae7dce6d1d972e89682a0886b10a44f68295fc

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.