Overview

Cricket lets a contract on Robinhood Chain use randomness that nobody can rig. The randomness comes from drand, a public beacon run by independent organisations that signs a new round every 3 seconds. Cricket verifies that signature on chain with the BLS12-381 precompiles the chain already has.

The problem

A contract is a deterministic machine. Whatever it can read from the chain, other people can read too, and often influence. So randomness built from the chain itself is only as fair as the people ordering blocks are honest and the players are unaware.

We checked the obvious source on Robinhood Chain: block.prevrandao returns the constant 1. Three eth_calls on 15 Oct 2026, all identical. A contract that uses it as dice always rolls the same number.

What Cricket gives you

• CricketBeacon: a stateless verifier. Give it a round number and the 48-byte signature, it returns the random number or reverts.
• CricketDraw: fair draws. Commit a list and a future round, anyone reveals the signature, the winners follow from it.
• An engine in JavaScript that does exactly the same maths, so any site or script can check a result without the chain. This website is built on it.

What you can build

Raffles and airdrops that choose holders, fair queues, loot drops, turn order in games, shuffles, sampling a subset of voters, a lottery-style box (mind the legal side). The common shape: commit to the rules and to a round that does not exist yet, then let the round decide.

What it is not

• Not a price oracle, not a bridge, not a token. Nobody needs to hold anything to use it.
• Not magic: it trusts that enough of the drand operators do not collude. See Security model.
• Not audited yet. See Limits and risks.