Research On Data Integrity And Destructibility Of Cloud Storage Based On SLA

With the rapid development of cloud storage technology,more and more enterprises and individuals choose to upload data to the cloud storage in order to obtain massive storage resources and reduce their own costs.However,cloud storage security faces significant challenges due to the uncertainty of physical control over the data.Users pay special attention to data security.On one hand,they require the data stored in the cloud to be complete;on the other hand,they also require the deleted data is unrecoverable.This paper starts with the description of the integrity and destructibility indexes in the Service-Level Agreement(SLA),proposes the indexes and schemes for third-party objective examination,which can serve as a reference standard for user selection and audit supervision to cloud service providers(CSP).The main research contents and results of this paper are as follows:1.Audit scheme for data integrity of cloud storage.The CSP usually promises multiple copies of backup in the SLA,but no effective examination mechanism is yet formed to verify whether the number of copies is compliant and whether the data is complete.In view of this situation,this paper proposes a dynamic multi-copy integrity audit scheme based on bilinear mapping:(1)A trusted third party is newly added to achieve the goal of public audit;(2)Mask operation is applied on data blocks to obtain multiple different copies,so as to confirm whether the number of copies conforms to the SLA;(3)Vector tags are constructed for each data block to reduce the computational complexity,for realizing the function of batch checking,locating and repairing data blocks;(4)Map-Version table is introduced to record the physical,logical and version serial numbers of data blocks,as the underlying support of dynamic data operation in the scheme;(5)Theoretical analysis and experimental results of computation,storage and communication consumption show that the scheme has better performance.2.Audit scheme for data destructibility of cloud storage.Traditional schemes are mostly deletion determination technology based on cryptographic design,but they ignore the transformation to destructible audit schemes.Usage of additional key storage mechanism also increases the cost of data storage to some extent.In view of this situation,this paper proposes a third-party destructibility audit scheme based on trusted strategies:(1)Key time point of CSP data destruction is defined in a standard way;(2)Testing process is simplified with strong operability and low cost;(3)Direct testing is conducted by a third-party audit institution to ensure that the process is objective and credible.Finally,experiments are carried out in the cloud environment to prove the feasibility of the scheme.3.SLA compliance audit tools are integrated,including examination of integrity and destructibility.Simulated tests are conducted in a light-weighted cloud environment,proving that the schemes mentioned above can detect CSP’s violation operations.