Research On Secure Multi-party Computation Scheme Based On Blockchain

With the continuous development of computer and network technology,the world has entered the era of data sharing.The large amount of data in the network environment provides a rich potential data resource for all industries.In order to maximize the benefits of data,parties wish to integrate and utilize data across organizations and industries.One of the main requirements is to perform multi-party data federated computing while ensuring data security and privacy.Reliable technical support is required to realize data federated computing.Among them,secure multi-party computation technology is considered as an effective means to realize data federated computation,and secure multi-party computation technology is also widely adopted due to its superior characteristics.The application of blockchain technology also further improves the reliability and practicality of secure multi-party computation technology,which can provide a trusted execution environment for secure multi-party computation tasks by combining the characteristics of blockchain technology,such as tamper-evident,decentralized,and open and transparent.Therefore,this thesis aims to design a blockchain-based secure multi-party computation scheme by taking secure multi-party computation technology and blockchain as the research objects.The main research work covers the following:1.In view of the lack of correctness,verifiability and fairness of calculation results in current secure multi-party computation schemes,a blockchain-based multiparty computation scheme is proposed by combining blockchain and secure multi-party computation technologies.The scheme uploads participant information and computation results to the blockchain and provides verifiability by controlling the whole computation process through smart contracts;ensures the correctness of computation results through incentive mechanisms.To address the problem of computationally participating nodes colluding to steal information and suspending contracts to destroy the fairness of the scheme,a fair computation node selection scheme is designed by generating random numbers through BLS(Boneh-LynnShacham)signatures and node credit values,and a smart contract is responsible for conducting the selection of proxy computation nodes.This scheme achieves fair and secure joint computation of multi-party data.This scheme achieves fair and secure joint computation of multi-party data.2.To address the problem that most of the current secure multi-party computation schemes are not resistant to quantum attacks and that the result querier cannot decrypt the results individually when they are obtained.We propose a blockchain-based secure multi-party computation scheme with multi-key full homomorphic agent re-encryption by using the NTRU cryptosystem,which has the ability to resist quantum computation attacks and has a simple and easy-to-implement structure,combined with multi-key full homomorphic encryption and agent re-encryption,and use the blockchain as a trusted storage and trusted execution environment to provide data security for multiparty computation.The scheme meets the requirements of verifiability,conspiracy prevention,individual decryption,and quantum attack resistance.