Every draw, published.

The logic

How the winners are chosen.

No one picks a winner by hand, and the admin cannot steer the result. The outcome is a fixed calculation on two things we do not control: who bought tickets, and a public random value.

1. 1

   Tickets close

   At the draw time (Sunday 20:00 UTC) no more tickets can enter that draw. Every ticket number in it is sorted in alphabetical order and joined into one list.

2. 2

   The list is fingerprinted

   We compute the SHA-256 hash of that list (the “ticket fingerprint”). Change a single ticket and the fingerprint changes completely, so the list we publish afterwards can be checked against it.

3. 3

   A public random value appears

   The random value comes from drand, a public randomness beacon run by a group of independent organisations. It publishes a new unpredictable value every 3 seconds, signed so it can be checked. We use the value for the round published at the draw time, so neither we nor anyone else can know it before tickets close, and we cannot pick a convenient one.

4. 4

   Winners are calculated

   seed = SHA-256(random value + ":" + fingerprint). For k = 0, 1, 2 …, take SHA-256(seed + ":" + k), read its first 8 bytes as a number, and take it modulo the number of tickets. That position in the sorted list is the next winner. If it was already picked, skip it. The first pick wins the grand prize, the next three the runner-up prizes, the next ten the lucky draws.

5. 5

   Published for everyone

   We publish the full ticket list, the fingerprint, the drand round and value, and the winners. The button on each result repeats steps 2 to 4 in your own browser and shows every calculation.

// Paste into any JavaScript console (Node 18+ or a browser) to check a draw yourself.
// tickets: the published ticket list (sorted). randomness: the drand value shown for that draw.
const sha = async (s) => [...new Uint8Array(await crypto.subtle.digest('SHA-256', new TextEncoder().encode(s)))]
  .map((b) => b.toString(16).padStart(2, '0')).join('')

async function winners(tickets, randomness) {
  const ticketsHash = await sha(tickets.join('\n'))
  const seed = await sha(randomness + ':' + ticketsHash)
  const picked = [], out = []
  for (let k = 0; out.length < Math.min(14, tickets.length); k++) {
    const d = await crypto.subtle.digest('SHA-256', new TextEncoder().encode(seed + ':' + k))
    const i = Number(new DataView(d).getBigUint64(0) % BigInt(tickets.length))
    if (!picked.includes(i)) { picked.push(i); out.push(tickets[i]) }
  }
  return { ticketsHash, winners: out } // 1st = grand prize, 2nd-4th = runner-ups, 5th-14th = lucky draws
}