基于安全多方计算的区块链智能合约执行系统

Smart Contract Execution System over Blockchain Based on Secure Multi-party Computation

智能合约是一种两方或多方缔结的、具有法律效力的可执行计算机协议,它作为区块链核心技术日益受到重视,然而如何保证数字资产中隐私信息在交易中的私密性,以及提供智能合约的抗攻击能力仍然是尚待解决的问题.本文通过提出基于安全多方计算(SMPC)的智能合约框架、面向线性秘密共享的公平SMPC算法设计、以及非阻塞信息传递接口等三方面技术,保障了计算节点错误下的安全群组通信,规范了基于SMPC的智能合约执行流程、语言结构和语法规范,保证了智能合约执行中的输入隐私性和计算正确性,从而增强了区块链中智能合约执行安全.

Smart contract is an executable computer protocol in compliance with the terms of interaction among two or more parties,and has legal effect in the real world.It is becoming more and more important as a core technology of Blockchain.However,how to ensure the confidentiality of private information hidden in digital assets and the resistance of smart contract against attacks is an important problem.This study proposes three techniques:a smart contract framework based on secure multi-party computation(SMPC),a fair SMPC algorithm built on linear secret sharing,and a non-blocking message passing interface(MPI).These techniques can be used to guarantee secure group communication after several nodes hit the fault,error,and failure.Moreover,the techniques regulate the workflow,language structure,and syntax specification of SMPC-based smart contract.In addition,the privacy of inputs and the correctness of computing result can be ensured during smart contract execution.Thus,the execution security of smart contract can be enhanced by the proposed techniques in the Blockchain.