Secure Smart Contract System Built on SMPC Over Blockchain

While smart contracts are praised widely, it should be noted that they have their disadvantages: lack of control over data protection and executive correctness or consistency. Aiming at this problem, we propose SMPC-based smart contract platform with three-layer structure: contract, computing, and group communication layer. In contract layer, we put forward SMPC-based smart contract framework, which gives the implementation process, language structure and grammar specification of smart contracts. In computing layer, fair SMPC algorithms based on general linear secret sharing scheme are designed to implement verifiable collaboration computing with input privacy and computation correctness. In group communication layer, the non-blocking broadcast is developed from non-blocking message passing interface (MPI)in order to ensure secure group communication in asynchronous networks with node and link failures. Finally, the results of simulation experiments with private currency transfers indicate that our platform is efficient and secure enough for common smart contracts.