Research On Complex Operation Outsourcing Algorithms In Cloud Environment

The development of cloud computing provides a new computing mode,which allows companies,organizations and individuals to rent computing and cloud storage resources from service providers to complete local computing tasks.The client or device with weak computing power can outsource their heavy computing tasks(for example,large matrix multiplication or algebraic computation)to cloud server in order to reduce the computation cost of users as much as possible,because the cloud has the powerful computing power.In recent years,outsourcing computing has attracted wide attention and has become a hot research topic.Along with the rapid development of outsourced computing,two major security challenges must be taken into consideration.The first challenge the user faces is data privacy.The input and output of the outsourced computation usually contains sensitive information that the user does not want to expose on the cloud server,and the cloud services are usually assumed to be unbelievable.Therefore,it is necessary to take security measures such as data camouflage,problem transformation and encryption to prevent user information leakage.The second challenge of the outsourced computing model is the verification of the correctness of the calculation results.As a result,the user must have the ability to verify the correctness of the results or authorize a verification agency to verify the correctness of results.The research of outsourcing schemes for matrix multiplication and modular exponentiation has important theoretical and application values.This thesis conducts in-depth research on existing outsourcing programs for scientific computing outsourcing and encryption algorithms,and focuses on outsourcing algorithms for matrix and vector multiplication and outsourcing solutions for modular exponentiation.The main research contents include the following aspects:(1)For the multiplication of matrix and vector,this thesis designs an efficient outsourcing scheme suitable for large scale matrix and vector multiplication in single server model based on the properties of matrix,vector and group.The theoretical analysis and experimental simulation are used to analyze the correctness,security and efficiency of the scheme.The experimental results show that the scheme has better security and higher user-end execution efficiency.(2)For the modular exponentiation,this thesis designs a modular exponentiation outsourcing scheme with the verifiable probability 1 based on the double server model,in which large scale matrix is used to hide data information.The scheme succeeds in protecting the privacy of the user's sensitive information and the calculation results.In addition,The security advantage of the scheme and the faster user execution efficiency are proved through experiments.(3)For the modular exponentiation,this thesis transforms the original modular exponentiation computing outsourcing problem into a new one,and designs a modular exponentiation computing outsourcing scheme based on the dual server model with the method of data logical partitioning.The scheme not only can fully protect the user information,but also has high efficiency and verifiable probability.