How to Verify a Bink Result

• Your committed server-seed hash (visible in Settings → Provably Fair before any round).
• Your client seed (visible in the same place; you can change it any time).
• The nonce of the round you want to verify (round number — also visible in your bet history).
• After seed rotation: the revealed server seed.

Take the revealed server seed and hash it with SHA-256. The output should match the committed hash you recorded before any bets were placed. If it matches, the server never changed the seed mid-session.

Compute HMAC-SHA256(serverSeed, clientSeed + ":" + nonce). The first 52 bits of the output become a number from 0 up to (but not including) 1; each game maps that number to its outcome (Dice to a roll, Roulette to a slot). Multi-step games such as Plinko take one HMAC per step, with the step number appended after the nonce, so every peg has its own roll.

If you don't want to run the math by hand, paste the triplet (serverSeed, clientSeed, nonce) into the live verifier at /provably-fair or the per-game verifier at /games/<game>/verify. It returns the exact outcome the server produced.

The outcome-mapper for every Bink Original lives in packages/crypto-utils/src/games/. It's open-source — you can audit the exact code that ran on the server for every round you played. Bink's own self audit walks that same code with published test vectors, so you can reproduce our checks alongside your own rounds.

If a single round's computed outcome diverges from what Bink showed you, the server tampered with the seed. That is the whole point of the design: you don't need to take Bink's word for anything, because the check is yours to run and the code that produced the result is published. Verify any round, any time.