Provably Fair Casinos

By | March 30, 2016

Something that has come to be known as Provably Fair is a method that enables an online casino to show that it handles the wagers in a fair way. Here’s a whitepaper of how it works on one Bitcoin casino.

1. The Client first starts a brand new game round and retrieves the a Hash from the Game Server.

2. The server is generating a random server number and server salt.

3. The server assigns a round id and responds with a SHA256 hash from the server number and server salt.

4. The client can use a pre-generated client number that the game client provides for you. When clicking Roll Dice, the number in the client number text box is sent to the game server, along with other wager details like bet size and the “Roll Under To Win”.

5. The game now combines the client number and server number into a resulting number.

6. The server number, resulting number and server salt are sent off to the client. The client now confirms that the server number and server salt are producing same hash that was retreived in step 3. The casino player can verify that the resulting number gives the correct outcome of the wager.

Results are verifyable and there’s 3rd party tools to verify Satoshi Dice rolls. Other sites like Primedice use slight variations of this technique.