Secure cloud storage model with hidden policy attribute based access control

We propose a secure cloud storage model that prominently addresses security and storage issues in cloud. The security is achieved by anonymous authentication of the users; where the attributes associated with individual users are hidden from cloud. This helps the cloud users to remain anonymous as well authenticated, for this digital signature based authentication scheme is developed. Also, a decentralized architecture is implemented for distributed key management. Further, Query driven approach is developed for hiding the access policies defined by individual user for his data i.e. the access is granted to the requester only if his credentials matches with the access policy. Homomorphic encryption scheme is used for encrypting the data that is stored in cloud. These data are sometimes vulnerable to loss or damages. In order to address this issue, an automatic retrieval mechanism is developed where the lost data is retrieved automatically.