Privacy-preserving searchable encryption scheme over encrypted data supporting dynamic update

Abstract

With the advancement of network technology, cloud computing services have become popular due to the on-demand availability of computing resources, large-scale data storage and distribution. Many users are influenced to outsource their private data to cloud servers to cut the costs of building by storing their data locally. Security and privacy protection of such outsourced data become a major security concern. To address this, the outsourced data is encrypted before it is stored on the cloud server. At the same time, users must be enabled to retrieve the data of their interest rather than going through all documents and picking up the ones that are required. This creates a need to search the encrypted data without allowing the cloud service providers know about the search query but still provide the clients with relevant documents. With data continuously changing over time, clients wish to keep their documents updated so as to maintain data consistency and enable other users to fetch the latest relevant data. However, while adding new keywords to documents, the potential positions of newly added keywords are leaked in the existing approaches. In this paper, an efficient and secure approach is proposed that returns the latest relevant documents and also preserves the privacy of updated keywords.