Providing freshness guarantees for outsourced databases
Min Xie, Haixun Wang, Jian Yin, Xiaofeng Meng · 2008
Database outsourcing becomes increasingly attractive as ad-vances in network technologies eliminate the perceived per-formance difference between in-house databases and out-sourced databases, and price advantages of third-party data-base service providers continue to increase due to economy of scale. However, the potentially explosive growth of database outsourcing is hampered by security concerns, namely data privacy and query integrity of outsourced databases. While privacy issues of outsourced databases have been extensively studied, query integrity for outsourced databases has just started to draw attention from the database community. Currently, there still does not exist a solution that can pro-vide complete integrity. In particular, previous studies have not examined the mechanisms for providing freshness guar-antees, that is, the assurance that queries are executed again-st the most up-to-date data, instead of just some version of the data in the past. Providing a practical solution for fresh-ness guarantees is challenging because continuously moni-toring data’s up-to-dateness is expensive. In this paper, we perform a thorough study on how to add freshness guaran-tees over proposed schemes (including authenticated data structure-based and probabilistic-based approaches) to pro-vide integrity assurance. We implement our solutions and perform extensive experiments to quantify the cost. Our ex-periment results show that we can provide reasonable tight freshness guarantees without sacrificing much performance. 1.