Searchable encryption technology makes it convenient to search encrypted data with keywords for people.A data owner shared his data with other users on the cloud server.For security,it is necessary for him to build a fine-grained and flexible access control mechanism.The main idea of this paper is to let the owner classify his data and then authorizes others according to categories.The cloud server maintains a permission matrix,which will be used to verify whether a trapdoor is valid or not.In this way we can achieve access control and narrow the search range at the same time.We prove that our scheme can achieve index and trapdoor indistinguishability under chosen keywords attack security in the random oracles.
展开▼
