Authenticating top-k results of secure multi-keyword search in cloud computing

Abstract

Cloud computing brings abundant benefits to our lives nowadays, including easy data access, flexible management, and cost saving. However, due to the concern for privacy, most of us are reluctant to use it. To protect privacy while making full use of cloud data, secure keyword search is proposed and attracts many researchers’ interests. However, all of the previous researches are based on a weak threat model, i.e., they all assume the cloud to be “curious but honest”. Different from the previous works, in this paper, we consider a more challenging model where the cloud server would probably be compromised. To achieve a privacy preserving and personalized multi-keyword search, we first formulate different users’ preference with a preference vector, and then adopt the secure k nearest neighbor (KNN) technique to find the most relevant files corresponding to the personalized search request. To verify the dynamic topk search results, we design a novel Multi-Attribute Authentication Tree (MAAT). In particular, we propose an optimization scheme to reduce the size of verification objects so that the communication cost between the cloud and data users is tunable. Finally, by doing extensive experiments, we confirm that our proposed schemes can work efficiently.