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

dffbabbf32f2625c610b87e6ea224ae4b7d9bcfe586a38100e03a14a76b64580

Seed

a053bba149a6fee07c9ea3a948935687a009e574d0fc59164b51bab1d7ab4f15 SHA-256 of "degen.match.seed.v1", a zero byte and the 32 seed bytes is the seed hash.

Bettor's seed

6385468f792c6655be17ff97942ccb08

Commitment

Batch 70,051, Merkle root 61ca835d0db2467aea2d1a86b59670a8ff1012cebcd469cdc328f4fad9ca4962. Recorded by Degen Protocol; on-chain publication is not available yet. See this batch and its Merkle tree

Merkle path

1. fe4a7626f1ff0d9ad4f18c9b942313537b0ebfa5df8ecbd0956e008764a2f70b
2. ea68aa3b4ce8752c5c70b97a582a0a38c5fde075f7251d3b10b182057e61d940
3. ff705ed8dd75341fb6f3f7761f05d0bfe101338fbadb8a641d7e11b15f00e88b

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.