IJCAT - International Journal of Computing and Technology, Volume 2, Issue 7, July 2015 ISSN : 2348 - 6090 www.IJCAT.org 283 KNN-R Data Perturbation Building confidential and Efficient Query Services within the Cloud 1 G. DIVYA , 2 SURESH KUMAR 1 M.Tech 2 nd Year, Department of CSE, CREC Tirupati, AP, India 2 Professor & HOD, Department of CSE, CREC Tirupati, AP, India Abstract - With the wide deployment of public cloud computing infrastructures, using clouds to host data query services has become an appealing solution for the advantages on scalability and cost-saving. However, some data might be sensitive that the data owner does not want to move to the cloud unless the data confidentiality and query privacy are guaranteed. On the other hand, a secured query service should still provide efficient query processing and significantly reduce the in-house workload to fully realize the benefits of cloud computing. We propose the RASP data perturbation method to provide secure and efficient range query and kNN query services for protected data in the cloud. The RASP data perturbation method combines order preserving encryption, dimensionality expansion, random noise injection, and random projection, to provide strong resilience to attacks on the perturbed data and queries. It also preserves multidimensional ranges, which allows existing indexing techniques to be applied to speedup range query processing. The kNN-R algorithm is designed to work with the RASP range query algorithm to process the kNN queries. We have carefully analyzed the attacks on data and queries under a precisely defined threat model and realistic security assumptions. Extensive experiments have been conducted to show the advantages of this approach on efficiency and security. Keywords - Cloud computing, Data storage, query processing, security. 1. Introduction Cloud computing is usually a model intended for which allows hassle-free, on-need network having access to a contributed pool of configurable processing resources (e.g., networks, servers, storage area, applications, as well as services) which usually might be rapidly provisioned and released with nominal management exertion or service provider interaction”. The important cloud offerings was cloud storage and it also remains a well known answer. Cloud storage is usually a type of networked online storage when the details are kept in virtualized pools of storage which might be generally being hosted from the third parties. Cloud storage enables data stored remotely being temporarily cached on mobile phones, desktop computers, or other Internet-linked devices. Security and cost will be the top issues in this particular field and range greatly, according to the vendor one choose. Regardless of the first success and acceptance with the cloud processing model as well as the extensive accessibility to providers and tools, several challenges and risks are innate to the present new type of computing. Cloud Computing is utilizing hardware and software as computing resources to produce service through internet. Cloud computing provides various service models as platform as being a service (PaaS), software as being a service (SaaS), Infrastructure as being a service (Iaas), storage as being a service (STaaS), security being a service (SECaaS), Data as being a service (DaaS) & much more. Because of this Paas, SaaS and IaaS are most widely used.  Cloud computing has four models as Public cloud: though that the service can be acquired to everyone public use.  Private cloud: In which service can be acquired to personal enterprise or organization.  Community Cloud: It permits us to share infrastructure between various organizations by