There are dozens of tools to pick a name online. Almost all share the same flaw: they ask you to trust them. You click, an animation plays, a name comes out. Nothing distinguishes it from a name chosen in advance, and nothing stops a re-run until the convenient one appears.
A classic random generator produces numbers unpredictable to the onlooker but perfectly controllable by whoever runs it: the operator picks the moment, the seed and the number of attempts. None of the three is visible from outside.
A proof is something else: a mechanism that lets someone who does not trust you reach the same conclusion anyway.
Before the draw, the organiser publishes the cryptographic fingerprint of a secret seed. The fingerprint does not reveal the seed, but it locks it in: no other seed can be presented afterwards without the fingerprint ceasing to match.
The commitment alone is not enough. A second ingredient is needed, unpredictable at commitment time: drand, a distributed randomness beacon produced by a network of independent servers. No single actor can predict or bend it, and anyone can authenticate it. The organiser fixes in advance which round will be used — a round not yet produced when they commit.
After the draw the seed is revealed, and the winner follows deterministically from the seed and the drand value. Anyone can check three things: that the revealed seed matches the fingerprint published beforehand, that the drand value is authentic, and that the computation yields that winner. That is what the verification page does.
The cryptography is only worth something if the entry list is beyond reach too. The list is sealed when entries close, and its fingerprint published with the rest.
Anti-fraud filtering applies before that fingerprint is computed, and its rules are public: mandatory double opt-in, disposable domains excluded, duplicates removed, rate limiting per IP. Filtering applied afterwards, or with varying rules, would be a back door.
Finally, a draw is scheduled at least 24 hours ahead: committing one second before drawing would prove nothing.
Entering is always free. No money comes from an entrant: only the organiser pays for the tool. That is also what keeps the operation outside gambling regulation.
An ordinary one, yes. A provably-fair draw cannot, because the commitment is published before the randomness exists.
The revealed seed, the drand round and the algorithm — all three are published.
The list can come from open sign-ups or a CSV import of up to a million characters, split into several imports beyond that.