Verify a Pothole Round

Why verify

In Pothole, where the pothole sits is decided by the server before your first km. The game shows you its SHA-256 fingerprint right away, without revealing the key. At the end of the round the key is revealed. If that key's fingerprint is identical to the one shown at the start, the key wasn't swapped along the way. And since the pothole's km is recomputed from the key, you can check that the result wasn't picked based on your decisions. The general idea is explained in provably fair, explained simply.

Where to find the key and fingerprint

1. During a round, open the "Provably fair" panel under the game: it shows the round's fingerprint.
2. At the end (pothole, cash-out or end of the road), the same panel shows the fingerprint, the revealed key and the result.
3. Copy both, come back here, pick the road you played and run the check.

Note the road: the same key gives a different result on Country, City or Expressway, because the thresholds aren't the same.

The verifier

Everything is computed in your browser, with its built-in SHA-256 function. Nothing is sent to SVRNG Play and nothing is stored.

The exact rule

This is the server's rule, and the one this tool uses:

• For each km i, compute SHA-256 of the text key:i (the key, a colon, the km number). Example: …a3f:1, …a3f:2.
• Take the first 8 hexadecimal characters, convert them to a number and divide by 2³² (4,294,967,296). That gives a draw u between 0 and 1.
• The threshold for km 1 is q(1) = 0.97 ÷ m(1); for the following ones, q(i) = m(i−1) ÷ m(i), where m(i) is the multiplier shown at km i.
• The pothole is at the first km where u ≥ q(i). If no km triggers it, the road is clear to the end.

As a result, the chance of reaching a km is exactly 0.97 ÷ its multiplier. Cashing out at any km therefore returns 97% on average; that's what the 97% RTP page explains.

What verification proves, and what it doesn't

It proves your round's result was fixed before your first km and follows the published rule. It doesn't prove you'll win, or that a round "was due": each key is drawn at random by the server, independently of previous rounds. Nobody, you included, can work out the key from the fingerprint; that's the whole point of SHA-256.