Stake provably fair verifier

Stake uses HMAC-SHA256, key: server seed, message: clientSeed:nonce:round. That output is then turned into a game result with a formula specific to each game, which is what this verifier recalculates.

Dice, Limbo, Plinko, Roulette, Wheel, Diamonds, Flip and Blackjack / Hilo / Baccarat cards. Mines, Keno, Dragon Tower, Chicken, Pump and Video Poker are not covered yet: Stake describes their shuffle in words, without the code. Crash and Slide use a separate hash chain.

Formulas from Stake's own provably fair pages. Stake and Shuffle generate their random numbers with the same published function, so the worked examples in Shuffle's documentation test that part for both. Stake publishes no worked examples for the individual games, and its site could not be reached from where we tested, so the game formulas have not been checked against Stake's own verifier. One assumption: Stake writes its Dice formula without rounding down; we round down because it is the only reading that gives a two-decimal roll.

Open the bet in your bet history, or the fairness section of the game. The client seed and the nonce are shown straight away. The server seed is shown only as a hash while it is in use: rotate your seed pair and the casino reveals the unhashed seed for all the bets made with it.

Because the server seed stays secret while it is active, otherwise you could calculate your next results in advance. Rotating retires the seed and reveals it. Finish any game in progress before you rotate.

Check the inputs first: the server seed must be the unhashed one, the client seed must be the one that was active for that bet, and the nonce must be the one of that bet, not the latest one. Check the game settings too, such as the number of mines or rows. If everything is right and it still differs, run the same values in the casino's own verifier and ask their support. This tool is independent and can have mistakes of its own.

No. The calculation uses your browser's built-in cryptography and nothing you type is sent to us or to the casino. A revealed server seed is already retired, so it cannot be used to predict future bets anyway.

It means that result was fixed by the seeds before you bet and was not changed afterwards. It does not remove the house edge, which is built into the payouts, and it says nothing about withdrawals or how the casino treats its players.