Build a Verifiably Random Lottery Smart Contract on Ethereum

How to create an Ethereum lottery

Photo by dylan nolte on Unsplash

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True randomness has been near impossible on Ethereum. This is because transactions need to be verified by multiple nodes on the network to be confirmed. If a smart contract function were truly random, each node that verified a transaction using that function would come to a different result, meaning the transaction would never be confirmed.

A recent announcement by one of the biggest players in the Ethereum ecosystem has caused excitement around this very problem. Using a system called a Verifiable Random Function (VRF), Ethereum smart contracts can now generate random numbers.

This means concepts that seemed a perfect fit with smart contracts but couldn’t be brought to life because they required random numbers now can be.

One such concept is that of a lottery.

Building a Lottery Smart Contract

Our lottery is going to have three phases. The first is open, where new numbers can be submitted by anyone…