Design of a Stored-value Card Platform Based on Smart Contract

Stored-value cards are used more and more widely. But there are some problems in the present stored-value card platform: 1. The service agreement of stored-value card is not clear enough; 2. The refund process of users is inconvenient; 3. The transfer of stored-value can not be realized among users; 4. The security of accounts is not guaranteed. Smart contracts are computer contracts written in code, which are enforced directly by computers. This paper proposes a stored-value card platform in which the service contracts are expressed with smart contracts. The smart contract is executed on the blockchain. Blockchain technology, in which accounts are decentralized and data is resistant to modification, is applied to improving reliability in the consumption process. The platform is built on the private blockchains of Ethereum, which is designed for small merchants. ECDSA (Elliptic Curve Digital Signature Algorithms) is used to asymmetrically encrypt accounts. Some functions, such as stored-value issuance, stored-value consumption, commodity purchase, are designed in this system.