Public auditing cloud data storage- bilinear pairing.
Cloud data security is concern for the client while using the cloud services provided by the service provider. In this paper we are analyzed various mechanisms to ensure reliable data storage using cloud services. It mainly focuses on the way of providing computing resources in form of service rather than a product and utilities are provided to users over internet. In the cloud, application and services move to centralized huge data center and services and management of this data may not be trustworthy into cloud environment the computing resources are under control of service provider and the third-party-auditor ensures the data integrity over out sourced data. Third-party-auditor not only read but also may be change the data. Therefore a mechanism should be provided to solve the problem. In this paper, we utilize the public key based homomorphism authenticator and uniquely integrate it with random mask technique to achieve a privacy-preserving public auditing system for cloud data storage security while keeping all above requirements in mind. To support efficient Handling of multiple auditing tasks, we further explore the technique of bilinear aggregate signature to extend our main result into a multi-user setting, where TPA can perform multiple auditing tasks simultaneously.