Secure and efficient querying over personal health records in cloud computing

Information seeking is becoming an indispensable activity in daily life, especially in the medical cloud. Body Area Network (BAN) is becoming more and more popular with respect to the development and popularity of mobile devices. People are starting to back up the medical data to cloud, make data accessible by the doctors from almost anywhere using mobile terminals. In this paper, we present an efficient and secure fine-grained access control scheme which not only achieves authorized users to access the records in cloud storage, but also supports a small set of physicians to write on the records. In order to improve the efficiency, we put forward a novel technique called match-then-decrypt, which is used to perform the decryption test without decryption. Also, the scheme outsources bilinear pairing operations to a gateway without revealing the data content, and thus largely eliminates this overhead for users to a great extent. The performance assessments demonstrate the efficiency of our proposed solution in terms of computation, communication, and storage.