On security of data storage in cloud computing via exact regenerating code

Cloud storage provides service to the user for storing and maintaining their data. The users can access their data from anywhere, independent of location and provides less storage and maintenance cost. As the cloud is unreliable so this data storage service introduces security challenges, such as Confidentiality, Integrity, Availability and Reliability of data. In this paper we propose a new approach which is based on EEMSR (Explicit Exact Minimal Storage Regenerating Code) with hash function which provides Reliability, Availability as well as Integrity. An EMSR code which is a Regenerating code, can exactly regenerate back a lost block with less repair traffic. An EMSR code is defined by the parameters (n, k, d) that permits data recovery from any k of n nodes, and also have the capability of repairing a failed node by connecting to any d nodes. We used hash function with EMSR to achieve Integrity of the data stored in cloud through Challenge-Response protocol.