Privacy-preserving Ciphertext-Policy Attribute-Based Encryption in Hybrid Cloud

Attribute-based encryption(ABE) has been widely studied recently to support fine-grained access control of shared data, but the file size and cost of computing make it hard to be widely used.This paper aims to solve the problem using hybrid cloud. This paper modify the existing privacy-preserving method to store some message with small size and low computing cost in the private cloud for matching, users could decrypt the file in the public cloud only after the matching phase under the "match-then-decrypt" method. The proposed construction is proven to be secure and the experiment result shows the solution is efficient and practical.