Partially policy-hidden attribute-based broadcast encryption with secure delegation in edge computing

The rapid growth of data has successfully promoted the development of edge computing, which is used for processing the data at the edge of network. The emergence of edge computing compensates for the network delay caused by massive data uploads to the cloud. However, the issues of data security and privacy protection still need to be resolved. In this paper, we propose an efficient ciphertext-policy attribute-based encryption (CP-ABE) scheme that for the first time simultaneously achieves partially hidden policy, direct revocation, and verifiable outsourced decryption. Specifically, in our scheme, the concept of partially hidden policy is introduced to protect private information in an access policy. In addition, after a revocation is successfully executed, the revoked users will not be able to access the message without affecting any other non-revoked users. Our new scheme leverages the outsourcing technique to minimize the overhead required of the user. We demonstrate that our scheme is secure under the Decisional (q - 1) Diffie-Hellman assumption and the Decisional Bilinear Diffie-Hellman assumption, as well as evaluating its performance using simulations. (C) 2019 Elsevier B.V. All rights reserved.