drand — public, verifiable randomness

drand is a distributed randomness beacon: a network of independent servers produces, at regular intervals, a collective random value. No one knows it in advance, and once published, anyone can verify that it is authentic.

Each value is a threshold BLS signature: a sufficient number of independent nodes must contribute their partial signature to reconstruct the complete signature. No single participant can therefore predict or bias the outcome. The final signature is then hashed to produce the randomness — and because a secure signature is unpredictable, so is the randomness.

The production network is operated by the League of Entropy, a consortium of independent organizations (including Cloudflare and Protocol Labs). This distributed infrastructure ensures that no single entity holds the randomness source.

Anyone can verify that a value is authentic by checking the final BLS signature against the network's collective public key — without having to trust a central authority.

Before each draw, DrawSeal publishes the hash of its server seed and fixes the drand round that will serve as public randomness. The winner is computed from the revealed seed and the drand value of that round. You can recompute the result yourself: you land on the same winner. That is what a provably-fair draw is.