Authorized Attribute-Based Encryption Multi-Keywords Search with Policy Updating

: Attribute-based encryption is cryptographic techniques that provide flexible data access control to encrypted data content in cloud storage. Each trusted authority needs proper management and distribution of secret keys to the user’s to only authorized user’s attributes. However existing schemes cannot be applied multiple authority that supports only a single keywords search compare to multi keywords search high computational burden or inefficient attribute’s revocation. In this paper, a ciphertext policy attribute-based encryption (CP-ABE) scheme has been proposed which focuses on multi-keyword search and attribute revocation by new policy updating feathers under multiple authorities and central authority. The data owner encrypts the keywords index under the initial access policy. Moreover, this paper addresses further issues such as data access, search policy, and confidentiality against unauthorized users. Finally, we provide the correctness analysis, performance analysis and security proof for chosen keywords attack and search trapdoor in general group model using DBDH and DLIN assumption.