Check the draw
Paste a receipt link. Your browser opens the seal with the key and works the winner out again, from scratch.
Waiting for a receipt
- Spun
- Names on the wheel
- Seal shown before
- Key shown after
- Winner the key gives
Every name and weight on the receipt
What the seal proves
Before the spin, your browser makes a secret key from 32 random bytes and fingerprints it together with the names, their weights and how many to pick. That fingerprint, SHA-256, is the seal you see under the wheel.
After the spin, the key is shown. Anyone can fingerprint the key and the names again and get the same seal. Change one letter, one weight or the key, and the seal no longer matches.
To pick, SHA-256 of the key and a counter gives a stream of numbers. Each pick takes a whole number below the total weight by rejection sampling, so no slice gets a sliver of extra chance.
What it cannot prove is that nobody chose the key on purpose. That is why the key is made in your own browser and never by us.
