A privacy-preserving multi-levels access control protocol for sensitive data sharing

Database as a service (DaaS) is a new paradigm based on the cloud computing platform. With the growing concerns on privacy, the user shope to have a security manner to store their data in the cloud. In order to improve the privacy protecting method for the sensitive data shared in the cloud, this paper proposes a privacy-preserving access control protocol based on multi-levels access control, Feldman (t,n) VSS protocol and ElGamal homomorphism property. Theoretical analysis shows that, the protocol could protect the privacy of both the data owners´ sensitive data, and the access control information, while providing multi-level access control strategies.