UnipickerDraw Whitepaper
Random · LESSON 5

DRAND — a random number the whole world sets

DRAND is a random number set not by one person but by the whole world together. Nobody can make it in advance, and everyone sees the same value.

Concept

Where are the DRAND servers?

Many organizations worldwide (Cloudflare, various universities and labs, and more) run the servers together. This group is called the "League of Entropy."

Many places each contribute a bit, and it is combined into one random number. So if one place lies it does not matter, and if one place stops it is still fine.

Learn more — DRAND official site drand.love
Concept

What is a "round"?

DRAND does not make one number and stop. It keeps making a new random number on a fixed schedule. Each one is called a "round."

Each round gets a number in order: 1, 2, 3, … Every time a new random number is made, the number keeps climbing. Right this second the whole world is making a new round — it never once stops.

Key point — the next round's number is knowable in advance (predictable), but that round's random value is only set once the time comes (unpredictable). So if before a draw you commit, "I will use future round number X," nobody can fix the result ahead of time, keeping it fair. That is why Unipicker commits to the "current round + 2" future round rather than the current one. Since the value of a round that has not arrived is unknown, no one can foresee or rig the draw result.
Experiment

Fetch a real DRAND number

Press the button below to fetch this very moment's number from a real DRAND server.

Anyone can know the round number in advance, but its value is set only when the time comes. So even the organizer cannot fix the result ahead.
But what if DRAND pauses for a moment? In the next lesson, meet the backup public random number made by NIST.