Research On Secure Multi-party Computing Method Based On Blockchain

With the increasing maturity of blockchain technology,more and more systems take blockchain as the underlying architecture.And the growing number of IoT devices is generating huge amounts of data.There is no doubt that these data will be more valuable after being processed and shared.But these data belong to different entities or individuals.Therefore,using secure multi-party computing to design the data processing and sharing scheme can well take into account the two requirements of data security and privacy protection.This thesis focuses on blockchain and secure multi-party computing technology to carry out correlational research.Based on the blockchain,this thesis researches from three different horizontal and parallel perspectives:secure multi-party statistical computing,secure multi-party ranking,and secure multi-party cloud computing commission.The research has realized data statistics,numeric sorting and cloud computing commission that can protect data security and privacy among multiple parties.The integration of cloud technology has expanded the blockchain ecosystem.(1)A safe and efficient secure multi-party statistical calculation scheme based on the blockchain.Although the blockchain provides a secure computing environment,the realization of data sharing between multiple parties still faces data security and privacy issues.To this end,this scheme implements data statistics and aggregation with a secure multi-party summation protocol as the core.The scheme also designs a data obfuscation and a one-time address strategy to protect the privacy of the data owner and receiver.Besides,this scheme also uses data segmentation technology and encryption methods to protect data.(2)A secure multi-party sorting scheme based on blockchain.To provide the correct ranking results of participants while protecting the data security and privacy of all parties,this new scheme optimizes the existing scheme.A new secure multi-party summation protocol and a sort generation algorithm are designed based on the sort code.The use of sum operation reduces computational overhead.The sort generation algorithm solves the problem of discontinuous sequence numbers in the sort results output by the sort code.(3)A secure multi-party cloud computing commission scheme based on blockchain.To integrate blockchain with more popular technologies,especially cloud technology,so as to expand the ecosystem of the blockchain.This thesis introduces cloud storage and cloud computing into the blockchain as the role of providing computing and storage services.This move provides blockchain nodes with outsourcing services for computing and storage,and also provides the possibility for smart mobile devices to participate in the core tasks of the blockchain more deeply.Based on the above three schemes,the safety analysis is carried out for their respective safety models,and the expressiveness,usability,and efficiency of the system are verified by a prototype system and simulation experiments.