Enabling Verifiable and Dynamic Ranked Search over Outsourced Data

Cloud computing as a promising computing paradigm is increasingly utilized as potential hosts for users’ massive dataset. Since the cloud service provider (CSP) is outside the users’ trusted domain, existing research suggests encrypting sensitive data before outsourcing and adopting Searchable Symmetric Encryption (SSE) to facilitate keyword-based searches over the ciphertexts. However, it remains a challenging task to design an effective SSE scheme that simultaneously supports sublinear search time, efficient update and verification, and on-demand information retrieval. To address this, we propose a Verifiable Dynamic Encryption with Ranked Search (VDERS) scheme that allows a user to perform top-<tex-math notation="LaTeX">K</tex-math><alternatives>K</alternatives> searches on a dynamic document collection and verify the correctness of the search results in a secure and efficient way. Specifically, we first provide a basic construction, <tex-math notation="LaTeX">VDERS⁰</tex-math><alternatives>VDERS0</alternatives>, where a ranked inverted index and a verifiable matrix are constructed to enable verifiable document insertion in top-<tex-math notation="LaTeX">K</tex-math><alternatives>K</alternatives> searches. Then, an advanced construction, <tex-math notation="LaTeX">VDERS</tex-math><alternatives>VDERS★</alternatives>, is devised to further support document deletion with a reduced communication cost. Extensive experiments on real datasets demonstrate the efficiency and effectiveness of our VDERS scheme.