Trapdoor Security Lattice-Based Public-Key Searchable Encryption with a Designated Cloud Server

Cloud storage technique has becoming increasingly significant in cloud service platform. Before choosing to outsource sensitive data to the cloud server, most of cloud users need to encrypt the important data ahead of time. Recently, the research on how to efficiently retrieve the encrypted data stored in the cloud server has become a hot research topic. Public-key searchable encryption, as a good candidate method, which enables a cloud server to search on a collection of encrypted data with a trapdoor from a receiver, has attracted more researchers’ attention. In this paper, we propose the frist efficient lattice-based public-key searchable encryption with a designated cloud server, which can resist quantum computers attack. In our scheme, we designate a unique cloud server to test and return the search results, thus can remove the secure channel between the cloud server and the receiver. We have proved that our scheme can achieve ciphertext indistinguishability under the hardness of learning with errors, and can achieve trapdoor security in the random oracle model. Moreover, our scheme is secure against off-line keyword guessing attacks from outside adversary.