1 Attribute-Based Homomorphic Encryption based Integrity Auditing for Secure Outsourced Storage in Cloud Saloni Atre 1 , Mayank Namdev 2 P.G. Student, Department of Computer Science and Engineering, SIRT, Bhopal, India 1 Professor, Department of Computer Science and Engineering, SIRT, Bhopal, India 2 ABSTRACT: Cloud computing is an enormous area which shares huge amount of data over cloud services and it has been increasing with its on-demand technology. Since, with these versatile cloud services, when the delicate data stored within the cloud storage servers, there are some difficulties which has to be managed like its Security Issues, Data Privacy, Data Confidentiality, Data Sharing and its integrity over the cloud servers dynamically. Also, the authenticity and data access control should be maintained in this wide environment. Thus, Attribute based Encryption (ABE) is a significant version of cryptographic technique in the cloud computing environment. Data integrity, one of the most burning challenges in secure cloud storage. Data auditing protocols enable a verifier to efficiently check the integrity of the files without downloading the entire file from the cloud. In this paper cloud data integrity checking is performed by introducing attribute-based cloud data auditing where users can upload files to cloud through some set of attributes and specify auditor to check the integrity of data files. Existing protocols are mostly based on public key infrastructure or an exact identity, which lacks flexibility of key management. In this research work Cloud data integrity checking is performed by introducing attribute-based cloud data auditing where users can upload files to cloud through some set of attributes and specify auditor to check the integrity of data files. Variable attributes are used to generate the private key and their performance is evaluated under variable attribute list. KEYWORDS: Cloud Computing, Data Integrity, Data Auditing, Data sharing, Security, ABE I. INTRODUCTION Cloud computing conception has been visualized as design of consequent generation for data Technology (IT) enterprise. The Cloud computing plan offers with dynamic scalable resources provisioned as examine on the Internet. It permits access to remote computing services and users solely have to be compelled to buy what they require to use, once they need to use it. However, information that is kept within the cloud, the security of the data, its confidentiality and integrity is that the major issue for a cloud user. Cloud computing has been flourishing in past years thanks to its ability to produce users with on-demand, flexible, reliable, and affordable services. Some examples of cloud services include online file storage, social networking sites, webmail, and online business applications. There are some benefits of cloud storage services i.e. easy access anywhere and anytime, scalability, resilience, cost efficiency, and high reliability of the data, due to these benefits of cloud storage services each and every individual prefers to handover their personal data to the cloud storage whose security remains in doubt these days. These resources could be quickly provisioned and can be relieved with nominal managerial power or service provider interaction. By outsourcing data, the data owner gave right to cloud service provider to perform any operation on data. Hence data owner suffers from loss of possession of data. Possession of data states the control of data which means that if data is on local systems then data owner has full control over any operation performed on data including block deletion, modification, and insertion. But if the data is on cloud storage server then cloud provider has all the power to control any operation performed on the data. Cloud provider can stop any operation on data, process any operation incorrectly and may produce incorrect results. The major problem with loss of data possession is that the cloud provider can hide such mistakes from data owner for some benefits. The cloud server may also face internal and external security issues including components failure, administration problems, and software bugs which can harm data owner’s critical data.