Multi Owner Based Group Sharing with Data Leakage Prevention in Cloud

Cloud computing is an emerging technology used to store and share huge volume of data. To ensure data security in cloud cryptographic techniques has been utilized however current encryption algorithms does not enforce privacy concerns over cipher text associated with multiple owners. The issues are co-owners of data do not know whether the data should be disseminated by the disseminator. In our proposed scheme we introduce a system which supports multi owner data sharing in cloud computing in secure manner. Here disseminator can share data to other users when the attributes satisfies the access policy of the encrypted data. To overcome privacy conflicts three policy aggregation strategies are considered such as full permit, owner priority and majority permit. In general, the authorized users can generate some search tokens and send them to the cloud for running the search operation. These search tokens can be used to extract all the cipher texts which are produced at any time and contain the corresponding keyword. Since this may lead to some information leakage, it is more secure to propose a scheme in which the search tokens can only extract the cipher texts generated in a specified time interval. Even an authorized user should decrypt the particular file within that periodic time it should be downloaded otherwise it wont be available for access. The security analysis and experimental results show our scheme is practical and efficient for secure data sharing with multi-owner in cloud computing.