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

86b991abf7048e4fa5d87c5a511e4bbdd7cb5fdd85663baa3c66d91af4afabd4

Seed

774e62ad1aa34ea02c239d12db8769550e5dbba6472cef1380958e2e45136484 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

45ffef7f6514102bc19fbcae44dfd885

Commitment

Batch 71,325, Merkle root 39cc2250d2b87fd705cb742d32cdd325205e556510c365e643d72704f696ab59. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. 0d7dc65d48d1551dd14923d6087425abf43cfda3d59d8ee5998b41a21163d277
2. 83c503c0b7e72c3b732de4ec45fd48a62689d58a8fa3a8dcb385acae862c4cde

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.