论文标题
使用结果实质化在加密数据上的动态天际线查询
Dynamic Skyline Queries on Encrypted Data Using Result Materialization
论文作者
论文摘要
天际线计算是一个越来越受欢迎的查询,在医疗保健,旅行和金融等领域中具有广泛的适用性。鉴于最新的外包数据库和查询评估的趋势,并且由于数据的专有性,有时是高度敏感性的性质(例如,在医疗保健中),因此必须在加密数据集中评估Skylines。几项研究工作承认了安全的天际线计算的重要性,但是现有的解决方案至少遭受了以下缺点之一:(i)它们仅提供临时安全性; (ii)它们过于昂贵;或(iii)他们依靠不切实际的假设,例如协议中有多个非批评方的存在。 灵感来自安全最近的邻居(NN)计算的解决方案,我们猜想最安全,最有效的计算天际线的方法是通过结果实现。但是,对于天际线来说,这种方法比在NN查询中更具挑战性。我们详尽地研究并提供了用于天际线结果预发行的算法,并对此过程进行了深入的理论分析。我们表明,在最大程度地减少存储开销的同时预先计算结果是NP-HARD,并且我们提供动态的编程和贪婪的启发式方法,可以更有效地解决问题,同时将存储保持在合理的水平。我们的算法是新颖的,适用于纯文本天际线计算,但是我们专注于加密设置,在该设置中,物质化将天际线计算的成本从小时减少到几秒钟。广泛的实验表明,我们在绩效方面显然胜过现有的工作,我们的安全分析证明,我们比竞争对手获得了较小(且可量化的)数据泄漏。
Skyline computation is an increasingly popular query, with broad applicability in domains such as healthcare, travel and finance. Given the recent trend to outsource databases and query evaluation, and due to the proprietary and sometimes highly sensitivity nature of the data (e.g., in healthcare), it is essential to evaluate skylines on encrypted datasets. Several research efforts acknowledged the importance of secure skyline computation, but existing solutions suffer from at least one of the following shortcomings: (i) they only provide ad-hoc security; (ii) they are prohibitively expensive; or (iii) they rely on unrealistic assumptions, such as the presence of multiple non-colluding parties in the protocol. Inspired from solutions for secure nearest-neighbors (NN) computation, we conjecture that the most secure and efficient way to compute skylines is through result materialization. However, this approach is significantly more challenging for skylines than for NN queries. We exhaustively study and provide algorithms for pre-computation of skyline results, and we perform an in-depth theoretical analysis of this process. We show that pre-computing results while minimizing storage overhead is NP-hard, and we provide dynamic programming and greedy heuristics that solve the problem more efficiently, while maintaining storage at reasonable levels. Our algorithms are novel and applicable to plain-text skyline computation, but we focus on the encrypted setting where materialization reduces the cost of skyline computation from hours to seconds. Extensive experiments show that we clearly outperform existing work in terms of performance, and our security analysis proves that we obtain a smaller (and quantifiable) data leakage than competitors.