An Efficient Key-Aggregate Keyword Searchable Encryption for Data Sharing in Cloud Storage

Abstract

One key focus of cloud storage is keyword search on encrypted data. In a cloud-based secure data sharing system, users need to search keywords on encrypted data in order to data confidentiality and query privacy. Moreover, a large number of trapdoors should be generated by users with his/her keys and submitted to the cloud. Some researches on searchable encryption with key-aggregate have been conducted in recent years, which shortened the number of keys and trapdoors to a constant. However, the computational overhead and communication costs are largely neglected in the literature. In this paper, we propose an efficient key-aggregate keyword searchable encryption (eKAKSE) scheme. Generally, this scheme does not need to generate substantial parameters when the system is established. It dramatically reduces the computational overhead in the case of resisting the eavesdropping problem. We formulate the security definitions for eKAKSE and prove its security. The simulation results show that the computational overhead of the proposed scheme is more efficient than that of other schemes.