In this paper, we define and explore proofs of retrievability (PORs). A POR scheme enables an archive or back-up service (prover) to produce a concise proof that a user (verifier) can retrieve a target file F, that is, that the archive retains and reliably transmits file data sufficient for the user to recover F in its entirety.A POR may be viewed as a kind of cryptographic proof of knowledge (POK), but one specially designed to handle a large file (or bitstring) F. We explore POR protocols here in which the communication costs, number of memory accesses for the prover, and storage requirements of the user (verifier) are small parameters essentially independent of the length of F. In addition to proposing new, practical POR constructions, we explore implementation considerations and optimizations that bear on previously explored, related schemes.In a POR, unlike a POK, neither the prover nor the verifier need actually have knowledge of F. PORs give rise to a new and unusual security definition whose formulation is another contribution of our work.We view PORs as an important tool for semi-trusted online archives. Existing cryptographic techniques help users ensure the privacy and integrity of files they retrieve. It is also natural, however, for users to want to verify that archives do not delete or modify files prior to retrieval. The goal of a POR is to accomplish these checks without users having to download the files themselves. A POR can also provide quality-of-service guarantees, i.e., show that a file is retrievable within a certain time bound.

PORs: Proofs of Retrievability for Large Files

computing is a network based environment where resources, information and software's are shared and provided to the users according to their demands. Though cloud computing is being widely used in various fields, it has certain drawbacks. Security issue is a concern in cloud computing. The confidentiality and data integrity should be guaranteed to the user who is putting their data over the cloud. This paper proposes a framework that would provide integrity of data of multiple users through Third Party Auditor (TPA) and proposes various algorithms to implement this framework. In the proposed framework concept of multi cloud has been used to provide best cost optimization for various requirements of user. The framework is also divided into three platforms namely: platinum for sensitive data storage, gold for less level of security and silver for least level of security on the data. Finally we have implemented different algorithms for the various platforms in the proposed framework. In the obtained results, we can find that the proposed framework is easy to implement and provides better performance by using the traditional algorithms of network security over the various issues of cloud computing.

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Framework to Improve Data Integrity in Multi Cloud Environment

Circa 2014. The cyber security landscape or the ‘ThreatScape’ as we call it, has changed, again. The emergence of new business models and technologies has seen a recent radical increase in vulnerabilities to which organisations are exposed. Modern organisations now operate as part of a complex, partially trusted eco- system comprising other organisations, a diverse range of third-party technologies, and end-users operating in a variety of organisational cultures. The need to meet organisational and business challenges such as increased productivity, lowered costs, and customer satisfaction has driven organisations to break the traditional ‘silo’ infrastructure model as they try to improve efficiency, engage more with customers and collaborate closely with partner organisations. Organisations have embraced cultures where employees work anytime and from anywhere.

Detecting and Preventing Data Exfiltration

Cloud Computing is an evolving technology because of it reduced capital expenditure, maintenance and provides dynamic resource pooling, virtualization, on demand service & high availability. Cloud computing has been envisioned as a next generation architecture of IT Industries. Security & privacy is the major hurdle in the cloud environment because of its open and distributed architecture. This paper explores the cloud security threats and also discusses the existing security approaches to secure the cloud environment. In this paper we also proposed a novel Tri-mechanism for cloud security against data breach which provide all around security to the cloud architecture.

Cloud computing: Security threats & control strategy using tri-mechanism

Cloud Computing is widely used technique for data storage on-demand but involves risk such as data security, privacy protection, access-control and data confidentiality. Present study is a survey of the popularly used encryption techniques that is helpful to secure sensitive information on cloud. A discussion of the fundamental challenges and issues/characteristics of cloud computing has been done. Identification of security and privacy issues within this framework are highlighted. Study of the widely used encryption techniques helpful in securing sensitive information on cloud is debated. Scope has been set for academicians and researchers. Diverse versions of the encryption techniques surveyed and analyzed to identify optimization features for cloud security.

Adopting information security techniques for cloud computing—A survey

Cloud computing is the one which offers infrastructure to the client on a pay as you use model by leveraging on the Internet technology As this model depicts the electricity billing it is often termed as utility computing It offers various services to the client based on the need The need of the resources can be scaled up or down on the basis of the requirement The IT sectors started using cloud service models As the use of cloud increases day by day the concerns of cloud also gets increased There are number of data breaches that are happening day by day that affect the cloud growth The major concern in adapting cloud is its security The companies have lot of data that gets increased each day enlarges the complication of data privacy and security The data that we talk can be classified as either stagnant data ie, for simple storage as offered by Amazon's Simple Storage Service (S3) or it can be vibrant that changes often The solution available to protect the stagnant data will be to simply encrypt the data before it gets stored in the server In order to solve the issues of vibrant data the techniques are being proposed to work out on the encrypted This paper is a survey of different security issues that affects the cloud environment and related work that are carried out in the area of integrity The technique proposed combines the encrypting mechanism along with the data integrity check mechanism The data are double wrapped to ensure no data leakage happens at the server side The data are also shared with users with proper access mechanism

R. K. Sivanandhan

Papers

Data confidentiality and integrity verification using user authenticator scheme in cloud