Enabling Verifiable and Dynamic Ranked Search over Outsourced Data

Abstract

Cloud computing as a promising computing paradigm is increasingly utilized as potential hosts for users&#x2019; massive dataset. Since the cloud service provider (CSP) is outside the users&#x2019; 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 <i>sublinear search time</i>, <i>efficient update and verification</i>, and <i>on-demand information retrieval</i>. To address this, we propose a Verifiable Dynamic Encryption with Ranked Search (VDERS) scheme that allows a user to perform top-<inline-formula><tex-math notation="LaTeX">$K$</tex-math><alternatives><mml:math><mml:mi>K</mml:mi></mml:math><inline-graphic xlink:href="liu-ieq1-2922177.gif"/></alternatives></inline-formula> searches on a <i>dynamic</i> document collection and verify the correctness of the search results in a secure and efficient way. Specifically, we first provide a basic construction, <inline-formula><tex-math notation="LaTeX">$\mathsf {VDERS}^0$</tex-math><alternatives><mml:math><mml:msup><mml:mi mathvariant="sans-serif">VDERS</mml:mi><mml:mn>0</mml:mn></mml:msup></mml:math><inline-graphic xlink:href="liu-ieq2-2922177.gif"/></alternatives></inline-formula>, where a <i>ranked inverted index</i> and a <i>verifiable matrix</i> are constructed to enable verifiable document insertion in top-<inline-formula><tex-math notation="LaTeX">$K$</tex-math><alternatives><mml:math><mml:mi>K</mml:mi></mml:math><inline-graphic xlink:href="liu-ieq3-2922177.gif"/></alternatives></inline-formula> searches. Then, an advanced construction, <inline-formula><tex-math notation="LaTeX">$\mathsf {VDERS}^{\star }$</tex-math><alternatives><mml:math><mml:msup><mml:mi mathvariant="sans-serif">VDERS</mml:mi><mml:mi>&#x2605;</mml:mi></mml:msup></mml:math><inline-graphic xlink:href="liu-ieq4-2922177.gif"/></alternatives></inline-formula>, 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.