How provably fair works
Intermediate · 7 min read · by Denis Satoshi
Обновлено:
Provably fair lets you cryptographically verify that a casino did not manipulate a result. Learn the server seed, client seed, nonce and HMAC-SHA256 flow.
Provably fair is a cryptographic system that proves a game result was not tampered with. It relies on three inputs: a server seed (chosen by the casino), a client seed (chosen by you), and a nonce (a counter that increments each bet).
Before play, the casino shows a hash of the server seed — a commitment it cannot change. Your bet result is computed as HMAC-SHA256(server seed, client seed:nonce), converted to a number, then mapped to the game outcome. After you rotate seeds, the casino reveals the original server seed.
You then recompute the result yourself. If it matches what the casino showed, the bet was provably fair. This makes prediction impossible and manipulation detectable — which is why 'predictor' tools are always scams.
Before play, the casino shows a hash of the server seed — a commitment it cannot change. Your bet result is computed as HMAC-SHA256(server seed, client seed:nonce), converted to a number, then mapped to the game outcome. After you rotate seeds, the casino reveals the original server seed.
You then recompute the result yourself. If it matches what the casino showed, the bet was provably fair. This makes prediction impossible and manipulation detectable — which is why 'predictor' tools are always scams.