Nonce
A counter that increases by one with each bet made with the same seed pair, so every bet gets a different result.
The nonce is the bet counter in a provably fair scheme. With the same server seed and client seed, the nonce starts at 0 (or 1 at some casinos) and increases by one for every bet.
Why it matters
Without the nonce, the same seed pair would produce the same result every time. The nonce makes each bet unique while keeping the sequence fully determined by the seeds, so you can recompute any bet later.
What to check
- The nonce should increase by exactly one per bet, with no gaps or repeats. Gaps can mean bets were skipped or replayed; our audits check for this.
- Note whether the casino starts counting at 0 or 1, since an off-by-one mistake will make verification fail.
Worked example
Your bet history shows nonces 0, 1, 2 and 3 for four dice rolls. To verify the third roll, you compute HMAC-SHA256(server seed, "client seed:2:0") and convert the bytes to a float, then to a roll.