Technology And Implementation Of Multiple Replica Data Integrity Verification In Cloud

With the rapid growth of data and development of cloud storage services,cloud computing shows many advantages,such as high efficiency,convenience,pay on demand,high scalability and so on.As a result,more and more organizations and individual tend to migrate their data to the cloud.For some important files,users can store multiple replicas to improve the security.Cloud storage brings people a lot of convenience,but it brings a series of security problems.This thesis analyzes the key technologies of data security in cloud,focuses on the integrity of multiple replicas,studies the requirements of efficiency,confidentiality,security in verification process,analyzes the shortcomings of the previous schemes,and puts forward the improvement scheme.The main contents of this thesis are as follows:Firstly,solving the client lacks of computing power and storage capacity in multiple replicas data integrity verification in cloud.This thesis proposes an efficient proxy signature scheme based on bilinear pairing by combining fully homomorphic encryption and proxy signature technology.In this scheme,replicas generation,signature generation and data block's tag generation are performed by proxy signers with strong computing power,and the scheme ensures the data security of users.Experiments show that the scheme has high computational performance.Secondly,realizing the dynamic operation of users to the multiple replicas in the cloud,combined with the existing flexible multiple replicas data integrity verification scheme and the characteristics of multi-branch tree,a dynamic flexible multiple replicas data integrity verification scheme based on bilinear pair is proposed.In addition,the scheme also supports user privacy protection and three-party verification.Experimental results show that the scheme has high security.Thirdly,building HDFS to simulate the real cloud computing environment,and realize the multiple replicas data integrity verification system.The module division,function division and implementation of the system are given.The program is written to simulate and test the scheme.It realizes the integrity verification requirements of legitimate users for multiple replicas in the cloud.In addition,symmetric encryption technology is used to protect the security of user data.