Research On Multiple Replicas Integrity Perservation For Saas

With the development of Internet technology, SaaS (Software as a service), has become the latest trend of modern software technology as a new Software application mode. Service provider will install the applications on their own servers, responsible for management and maintenance of the software. SaaS model can reduce the cost of maintenance and management for tenants, and support online customizing and pay-for-use. It improves the resource utilization, and solves the problem of lack of storage resource and computing resource for the small and medium-sized enterprises.As cloud computing is developing, SaaS application data storage is shifting from single node to multiple nodes in the cloud storage. To ensure the reliability of data storage, multiple replicas of the data need to be stored in different nodes in the cloud. However, the untrustworthy service provider is responsible for the storage and management of the users’data, which makes the users lose the control of the data. At the same time, to prevent external malicious attacks, the service provider may delete, forged or tampered with replicas of the users for their own benefit. It affected the availability of the data seriously, causing immeasurable loss to users, also making the service provider’s reputation affected. So how to ensure the integrity of copies stored in the cloud becomes a key issue.This paper starts from some existing data integrity verification method, mainly contains the outsourced database integrity verification methods, the cloud data integrity verification method and multi-tenancy integrity verification method. Firstly, this paper introduces the mature outsourcing database integrity verification methods, mainly including the method based on digital signature, the method based on the challenge-response, and the method based on probability model. Then analyze the advantages and disadvantages of each method. But the storage architecture of multi-tenant sharing database in SaaS, the influence of the application requirements (tenants can flexibly customize security attributes) to multi-tenant data integrity are not considered. Secondly, introduce some existing integrity research method of the cloud data, and multiple replicas of the integrity verification method. There is not much information about it.Then, this paper introduces the multiple replicas integrity perservation architecture of the SaaS data. Bring in the trusted third party (TTP) that is used for identity authentication and integrity perservation strategy of customization and management. Based on the three parties’interactions model, multiple replicas of data integrity is confirmed, and the three parties’interaction is expounded. In addition, according to the characteristics of the SaaS model, this paper describes the four maturity model. Considering the above this paper proposed the multi-tenant data management model based on multi-tenancy data-sharing storage model and replica-place policy.Thirdly, this paper presents an integrity verification framework of multiple replicas, the double-layer authenticating construction which based on MAB-Tree authenticating construction. It allows the third party to take periodically sampling for the replicas data of users in order to prevent replicas data to be tampered, deleted, and added. We achieve the isolation of different tenants’ replicas and dynamic data operations.Finally, analyze the security and performance of the mechanism. Extensive experimental analysis of the relationship between sampling rate and cycle proves the validity and feasibility of the scheme in this paper.