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

1e41186ee28bbec363e0e295d05586de96ddb9697693e4f31c36603c36f22961

Seed

4b099015d20ceee68b1d19e96d1ee64ae649f054d0018b009d491fb7859e78ae SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

b47ca0078c403f28dc527e041b913ba0

Commitment

Batch 72,328, Merkle root 2ae34de588b955b4f3e7bf0af112488ec7d89f078f8e92ae88a21f004ee0cc33. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. 669346621ca0c01e49690f2148a91f2f3bdaabbc84e4dc131f0c307a506dbed7
2. 791385edc8f929873b6c4f5d397490808d281f82f6b35cbba9a65808b096e043

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.