Stud Coin (HAND, ShowHand) uses the ERC20 Ethereum underlying protocol to become a global entertainment game token, exempting a trusted third party as a payment gateway. Our platform is driven by the community to develop decentralized games. The operation logic of Stud Coin is determined by the smart contract released in advance, and no central organization can manipulate it. In terms of the security of entertainment game payment, the security guaranteed by the KECCAK256 encryption algorithm has not been cracked so far. As a third-generation secure hash algorithm, under the influence of the "avalanche effect", even the slightest change in the input will produce a completely different hash value, with extremely high stability and extremely low collision degree, The possibility of brute force cracking is completely ruled out.