Fig. System Model

In this Paper we propose a model for provable data possession (PDP) that allows a client to store the data at an entrusted server to check that the server contains the original data without retrieving it. This model produces probabilistic proof of possession by sampling random block sets from the server, which significantly decreases I/O costs. To verify the proof the client maintains a steady amount of metadata. The challenge/response protocol sends a small, constant amount of data, which reduces communication of the network. However, the PDP model for remote data checking supports more data sets in extensively-spreaded storage systems. We propose two provably-secure PDP schemes that are more efficient than previous solution, when compared

[15] W. K. Ng, Y. Wen, and H. Zhu. Private data deduplicationprotocols in cloud storage. In S. Ossowski and P. Lecca, editors,Proceedings of the 27th Annual ACM Symposium on Applied Computing,pages 441–446. ACM, 2012.

We would like to provide the benefits of cloud computing without any troubles to propel in the direction it is designed for. This is to be achieved by preventing the owner's data from all risks associated and providing a cloud model that is more secure and efficient. The proposed model shall overcome the security risks defined by the security functions over cloud computing, as follows in (Passent M. et al., 2015):

The economic case for cloud computing is compelling and at the same time there are striking challenges in its security. The concepts of cloud computing security issues are fundamentally new and intractable. What appears new is only relative to traditional computing that has been practiced since several years. Many such security problems have been giving attention since the time-sharing era. Cloud computing providers have and can build datacenters as large due to their expertise in organizing and provisioning computational resources at as low cost as possible.

Several researchers have addressed the issue of depending on a single cloud storage service, such as cite {AbuLibdeh2010} cite {Scalia}, and they believe that adopting multiple cloud storage services is a useful approach to tackling the problems associated with the dependence on a single cloud provider. Simply, This method combines several independent cloud services and considers them as one cloud. Although the distribution of data among several cloud storage services increase availability, performance, and reduces the probability of losing data, it may increase the amount of storage and bandwidth used and as a result, the cost rises. Scalia cite {Scalia} introduced a cloud brokerage solution that continuously adapts the placement of data, based on files access statistics among several cloud storage services to minimise the storage cost, improve the data availability, and eliminate vendor lock-in risk. However, The work does not evaluate the impact of the system on the latency time. HAIL cite {Bowers2009} used the principle of RAID to distribute files across a collection of cloud storage to enhance the availability of data and remotely manage data security risks (i.e. data integrity) in the cloud by employing the Proofs of Retrievability (PORs) system. Although this work shows a reduce in storage cost, they do not consider the effect of access patterns on the network cost. Besides, they assume that

From the viewpoint of data security, which has always been an important form of quality of service, Cloud computing surely poses new challenging security threats for number of reasons. Firstly, traditional cryptographic primitives for the purpose of data security protection cannot be straight accepted due to users loss control of data under cloud computing. Therefore, verification of correct data storage in the cloud must be attended without accurate knowledge of the whole data. Considering different kind of data for every user stored in the cloud and the requirement of long term continuous security of their data safety, the problem of checking correctness of data storage in the cloud becomes even more challenging.[1]

The ever growing need for the data in Information technology organizations has always lead to invent new services to meet the data needs, whether it is in the form of software, platform, hardware or storage. Cloud computing provides this services to organizations with cost effective methodologies like pay per service, network access, on-demand self-service. Organizations no more have to worry about storage overhead. This services has made huge impact on the organizations business process (Q. Wang, C.Wang, and Ren) (2011). At the same time with increase in technological services, the ever growing services are restricted due to security. Organizations use storage as a service to store their data remotely over cloud however the security of data is not guaranteed which leads to problems like data integrity, data availability, and data correctness. Various models has been proposed to address this data integrity concern over cloud (Chakraborty, Dhami, bansal), (2013).

Abstract - Cloud Computing is huge computing, it is the internet based computing, where all users can remotely store their data into the cloud so as to enjoy the latest and high quality applications and services. In outsourcing data , users can be relieved from the burden of local maintenance and data storage .Thus, enabling public auditability for cloud data storage security is of difficult so that users can resort to an external audit party to check the integrity of outsourced data when needed. To securely introduce an effective. The following two fundamental requirements to securely introduce an effective third party auditor (TPA) .1) The third party auditing process should bring in no new vulnerabilities towards user data privacy. 2) TPA introduces no additional on-line burden to the cloud user. TPA should be able to efficiently audit the cloud data storage. 3) TPA should audit the data for checking the integrity of that data. In this we propose for privacy-preserving public auditing for cloud data storage.To enable the TPA to perform audits for multiple users simultaneously and efficiently.We also doing batch auditing for multiple users data.

Usage of remote servers via internet to store, manage and process data instead of using a personal computer is known as Cloud computing. It’s a set of Information Technology services with the ability to scale up or down their service requirements. Most of the cloud services are provided by a third party service provider. In cloud computing, organizations can utilize IT services without in advance investment. Despite its benefits obtained from the cloud computing, the organizations are slow in accepting it due to security issues and challenges. Security is one of the major problems which hinder the growth of cloud. It’s not wise to handing over the important data to another company; such that clients need to be vigilant in understanding the risks of data infringement in this new environment. This paper discusses a detailed analysis of the cloud computing security issues and challenges. (Ayoleke)

We consider a cloud computing environment consisting of a cloud service provider (CSP), a data owner, and many users [few with read and few with both read/write permission]. The CSP maintains cloud infrastructures, which pool the bandwidth, storage space, and CPU power of many cloud servers to provide 24/7 services. The CSP mainly provides two services: data storage and re-encryption. After obtaining the encrypted data from the data owner, the CSP will store the data. On receiving a data access request from a user, the CSP will re-encrypt the ciphertext based on attributes, and return the re-encrypted ciphertext.

To address the issue of data deduplication there has been many schemes introduced in cloud computing. The main goal was to lower the resources cost from the cloud server. Data deduplication increases the volume of resources for data storage and limits it to consumers. As cloud computing offers vast and heavy data storage service there is a possibility of duplicate data storage in a server or multiple servers. Many techniques implemented till now focuses on security issues and sided the issue of data duplication on cloud server. To utilize the available resources in a very official and implicit manner there is a need to verify data of an individual or an organization where data is being stored in duplicates in cloud server. Information

Abstract— Data de-duplication is one of essential data com-pression techniques for eliminating duplicate copies of repeating data, and has been widely used in cloud storage to reduce the amount of storage space and save bandwidth. To protect the confidentiality of sensitive data while supporting de-duplication, the convergent encryption technique has been proposed to encrypt the data before outsourcing. The main motivation behind using this technique is making convergent encryption practical to capably and consistently manage a huge number of convergent keys and achieving competent and consistent key management in secure de-duplication. At we first introduce a baseline approach in which each user holds an independent master key for encrypting

G. Ateniese, R.C. Burns, R. Curtmola, et al. [3] the proposed purpose behind Provable Data Possession (PDP) was to check the servers, validate the integrity of data which were stored at doubtful servers and find the illegal actions performed like data modification and deletion. It did not consider the dynamic data auditing and various reasons behind data

We can protect the data on cloud by decreasing its value to the attacker or intruder.We can achieve this by seeding false information in other word using disinformation attack. We imagine thatsecure cloud services can be implemented given six other security features:

Abstract: Cloud technology is very constructive and usefulin present new technological era, where a person uses the internet and the remote servers to give and maintain data as well as applications. Such applications in turn can be used by the end users via the cloud communications without any installation. Moreover, the end users‟ data files can be accessed and manipulated from any other computer using the internet services. Despite the flexibility of data and application accessing and usage that cloud computing environments provide, there are many questions still coming up on how to gain a trusted environment that protect data and applications in clouds from hackers and intruders. Cloud storage should be able to store and share data securely, efficiently, and flexibly with others in cloud storage. The costs and complexities involved generally increase with the number of the decryption keys to be shared. The encryption key and decryption key are different in public key encryption. Since we are proposing new era of Aggregate key cryptography. To produce constant length ciphertext is also one of important task that we have materialized. In this paper, we propose a simple, efficient, and publicly verifiable approach to ensure cloud data security while sharing between