Verify a result, not a marketing badge
“Provably fair” should describe a reproducible process. It does not establish a licence, good value or the ability to withdraw. Before wagering, inspect the operator’s published verification instructions; if they are incomplete, do not assume another site’s algorithm applies.
- Save the commitment before playing. Record the hash of the hidden server seed, your client seed and the round nonce. A hash shown only after the result is not proof of an advance commitment.
- Get the revealed server seed. This usually requires rotating a seed pair. Do not expose an active unrevealed seed or your login credentials to an outside tool.
- Match the hash. Recompute the published hash function over the seed using the exact encoding. The output must match the pre-round commitment.
- Reproduce the round. Follow the operator’s actual algorithm: hash versus HMAC, key/message order, separators, nonce and any cursor are significant. Different games can use different conversions.
- Check the outcome mapping. Confirm how the random number maps to multiplier, colour or item ranges, and compare the ranges with published probabilities.
- Keep the record. Save the round ID, commitment, revealed seed and calculated output. A mismatch needs investigation; never simply replace the recorded nonce until a result matches.
Hash verification alone is not enough
SHA-256 matching demonstrates that a revealed seed fits the commitment. It does not independently verify the mapping from bytes to the displayed outcome. The game may still have a substantial house edge, and a correct result says nothing about custody, trading access or withdrawals.
Why we do not publish one universal formula
Some systems use HMAC-SHA256; others combine inputs differently or use more than one output block. Copying a formula between operators can produce a false mismatch. We have not performed a current implementation audit of named operators for this article, so this checklist is not a certification of any site.
For background, see MDN’s digest reference and RFC 2104 on HMAC. Read our provably fair guide and the game-edge comparison before confusing reproducibility with profitability.
