Enter a number between 1 and 1,000 below
Lottereo is a lottery built on the Ethereum Blockchain. You can buy a ticket for 0.1 ETHER, which gives you the right to guess a number between 1 and 1,000. All the money paid is added to the pot for the draw. At the date and time specified, a number between 1 and 1,000 is randomly selected. The pot (minus a 10% administration fee on all tickets sold) is divided between the winners and they are immediately paid into the wallet they used to purchase the ticket. If there are no winners, the pot is “rolled over” into the next draw.
You first need to have some Ether, which you can purchase at an exchange like Kraken. At the moment, because of the need to securely "sign" a transaction without revealing your wallet private keys, you also need either a special browser or a Chrome plugin to interact with Lottereo. But once you have those two things (the money and the special browser), it’s easy! Just press Play above and off you go!
Well, the code is publicly available here, so you can see exactly how it works. We have blogged about how it works here and here, as well as about how to ensure a truly random number is selected here; and about the difficulties of keeping the process going from draw to draw here (hint: this is the only bit of the Lottery in which you need to trust us).
In the brick-and-mortar world, a lottery draw is an event where three things need to happen:
Players need to buy tickets and trust that these are entered in the draw.
A draw needs to take place where numbers are selected in a trusted random.
Everyone needs to truststrong> that the winner(s) are paid a portion of the pot in a fair way.
Now, up until now the trust factors have been held by a third party, e.g. the National Lottery. Everyone trusts them to sell the tickets, draw numbers transparently and pay the winners.
But using Ethereum we can replace all the third party trust:
Buying tickets. Because you pay with your wallet into a contract in the Ethereum blockchain, you know exactly where the money went (and can check it) and we know where the money came from (in case we need to pay out).
Doing the draw. The code for the draw is public and auditable. You can decide whether you trust it or not.
Paying the winner(s). Again, this is in the code for the draw. If the code runs and a winner or winner exists, they will get paid (if you trust the code).
All of this is:
Anonymous (or pseudonymous). You play with your Ether wallet address. You get paid to your Ether wallet address. No need to register.
Totally transparent and auditable. For every draw, all the data is there in the blockchain, so anyone can go and figure out if it was done correctly.