FAQ: Is Ethex provably fair?

Yes, it is. Gameplay is controlled by an Ethereum smart-contract that compares your bets against blockchain data (block hashes). Block hash is the result of a cryptography function that is calculated from the list of transactions included in the very same block.

There is no way to know the hash before transaction is included in the block and there is no way to change the block hash, due to Ethereum’s consensus mechanism. The Ethex contract is open source and publicly available. Any party can audit the contract as well as inspect any transaction to make sure that neither Ether nor malicious players are influencing the results.

Read the security audit of Ethex smart-contracts by SmartDec.