In crypto gambling, trust is good — verification is better. Provably fair technology makes it mathematically impossible for a casino to manipulate results without detection.
This verifier uses the industry-standard HMAC-SHA256 algorithm. Enter the seeds provided by the casino after a round ends, and independently confirm that the result hash matches the game outcome. If the hashes match, the round was fair. If they don’t, the casino tampered with the result.
Standard HMAC-SHA256 verification.
How to Use the Verifier
To verify any bet, open the “Bet Details” or “Fairness” tab on the casino website and collect three values:
- Server Seed (Revealed): The casino’s secret key. You only see the unhashed version after the seed pair rotates or after you manually reveal it.
- Client Seed: The key your browser generated (or a string you entered manually).
- Nonce: The bet number in your current session (1, 2, 3…).
Click Verify. The tool generates a Result Hash. Compare it to the value shown on the casino’s website — if they match exactly, the outcome was predetermined and not manipulated after your bet.
Verification by Game Type
Different platforms use different hashing algorithms and seed structures. Here’s how verification works for the most popular games:
Aviator (Spribe) — SHA-512, 3 Client Seeds
Aviator uses SHA-512 (not SHA-256) and combines seeds from three different players, making it unique among crash games.
- After a round ends, click the Green Shield icon in the Aviator interface.
- Copy: server seed, client seed 1, client seed 2, client seed 3, and the nonce.
- Concatenate all values with no spaces or separators.
- Hash with any free SHA-512 tool online.
- Compare your hash to the one Aviator displays. Match = fair round.
For the full formula that converts the hash into a crash multiplier, see How Aviator’s Provably Fair Algorithm Works.
Stake / BC.Game / PrimeDice — HMAC-SHA256
Most crypto casinos use HMAC-SHA256 with a single client seed. Use the verifier above directly:
Enter your server seed, client seed, and nonce into the tool above. The output hash should match the casino’s displayed result.
Bustabit — HMAC-SHA256 Hash Chain
Bustabit uses a hash chain: each round’s hash is the input for the next round’s hash, working backwards from a published terminating hash. This means all outcomes in a cycle are predetermined before the first round begins. Verification involves checking that consecutive hashes chain correctly.
SHA-256 vs SHA-512: Which Games Use What?
| Platform | Hash Algorithm | Client Seeds | Verify With This Tool? |
|---|---|---|---|
| Stake.com | HMAC-SHA256 | 1 | ✅ Yes |
| BC.Game | HMAC-SHA256 | 1 | ✅ Yes |
| PrimeDice | HMAC-SHA256 | 1 | ✅ Yes |
| Bustabit | HMAC-SHA256 (chain) | 1 | ✅ Yes |
| Aviator (Spribe) | SHA-512 | 3 | ⚠️ Use SHA-512 tool |
| JetX (Smartsoft) | SHA-256 | 1 | ✅ Yes |
Both SHA-256 and SHA-512 are from the SHA-2 cryptographic family and are equally secure. The difference is output length (64 vs 128 hex characters) and the number of seed inputs — not security strength.
Why Verification Matters
The provably fair system only protects you if you actually check. A casino that publishes commitments but knows nobody verifies them could theoretically serve manipulated results. Independent verification tools like this one — separate from the casino’s own interface — provide a second layer of trust.
Understanding the algorithm behind the hash also helps you avoid predictor scams. If you know how the crash point is derived from a hash, you understand why “predictor apps” are mathematically impossible. For probability calculations at any target multiplier, use our Crash Game Probability Calculator. To see how these probabilities translate into strategy decisions, read our Crash Game Strategy Guide or use the Auto-Cashout Optimizer to compare EV across multiplier targets.