Research On Integrity Audit Mechanism Supporting Data Recovery In Multi-cloud Storage Environment

Since the single cloud storage environment gradually exposed the problem that single point failure and single point locking,more and more users tend to migrate files into multiple cloud service providers(CSP)for storage.This new storage paradigm is supported by multi-cloud management projects,which makes the user process data in the multi-cloud environment more simple and efficient.However,the development of multi-cloud storage technology brings new problems,such as,the ability of users to integrate resources,computing and management is limited,so that the complex work needs to be authorized to the third party agent(TPA)for implementation.And multicloud environment contains a variety of heterogeneous servers,and the distance between nodes is far,so the transmission cost is high.To solve the above problems,this paper proposes a secure storage scheme and a data transmission path optimization scheme in the multi-cloud storage environment.The main work of this project includes:1.Research and put forward the scheme of data security storage and integrity audit in the cloud storage environment.Based on the all-or-nothing transformation(AONT)method,this paper uses hash function and pseudo-random permutation function to improve the efficiency of data transformation.Then,the users send the converted and encrypted files to TPA,and TPA establishes a connection with two or more CSPs by using multi-cloud management project,so as to complete the reasonable distribution of data in the cloud environment.In addition,the user authorizes TPA to perform the integrity audit task of cloud data,and TPA uses the homomorphic verification technology of tags to ensure that the remote nodes store user data correctly.Finally,through the security analysis,it is proved that the encryption mechanism in this paper can resist the attacker to pry into the privacy information and ensure the security of the outsourcing data.In addition,TPA can successfully complete the task of data integrity audit in a multi-cloud environment through multi-cloud management technology.2.In order to enhance the reliability of the system,this paper adds the regeneration code coding strategy based on the above data storage scheme to support the accurate regeneration of damaged data.Firstly,TPA uses a simple and efficient PM-MSR code to process the encrypted files uploaded by users before calculating the data block labels.Then,according to the difference of storage capacity and repair bandwidth of heterogeneous servers,the nodes are divided into super nodes and ordinary nodes.And the encoded files are divided into blocks and the storage nodes are reasonably allocated,and the backup is created for the super nodes.Secondly,considering the long distance between nodes,this paper proposes a path optimization scheme for the new node to repair the damaged data.Finally,according to the experimental verification,the transmission cost of the optimized data repair path is significantly lower than other repair schemes.In this study,we build a multi-cloud architecture to achieve data storage,integrity audit and data repair functions.Experimental results show that the improved AONT conversion mechanism proposed in this scheme reduces the computational overhead compared with the original method,and compared with the traditional encryption method,the encryption method combined with the conversion algorithm in the study improves the data privacy without increasing too much computational overhead.Moreover,TPA achieves data integrity audit in the cloud storage environment through multi-cloud management technology.In addition,this paper uses PM-MSR code to encode files,and proposes an optimization scheme of data repair path.Compared with the existing methods,this scheme significantly reduces the cost of data repair.