Privacy and Secure Revocable Data Access Control in Multi-Authority Cloud Storage

ABSTRACT Cloud users uses "Cloud storage" service to host their data in the cloud. Access control service provided by cloud is used for giving protection against unauthorized access to data.Ciphertext-Policy Attribute-Based Encryption (CP-ABE) is mostly considered for data access control in cloud storage. The existing CP-ABE is difficult to apply in multi-authority cloud storage due to the attribute revocation problem. The proposed revocable multi-authority CP-ABE scheme provides solution to the attribute revocation problem. The proposed scheme updates the components of the revoked attribute only and generates latest secret keys for the revoked attribute and forwards it to the non revoked users who have the attributes as revoked attributes. The Backward security and Forward security is maintained. If the revoked user enters into the system again by doing the registration process means, the particular user is identified via the identity card detail in the revocation list and they are not allow in the system, so that these users are stopped at the registration phase itself.