In this paper, we propose a highly accurate, fully secure document similarity search (FSDS) scheme that makes use of both a novel variant of the secure $K$-NN algorithm and somewhat homomorphic encryption (SWHE). The scheme provides data, query and search pattern privacy and is amenable to access pattern privacy. We provide formal security analyzes of both the original and the new secure $K$-NN algorithms and show the latter is IND-CPA secure. We also rely on IND-CPA security of the SWHE scheme to meet the strong privacy claims. The scheme provides a speedup of about two orders of magnitude over the schemes using only SWHE while its overall performance is comparable (and faster for certain cases) to other schemes in the literature with weaker forms of privacy claims. We present implementation results including those from the literature pertaining to response times, storage and bandwidth requirements and show that the proposed scheme facilitates a lightweight client implementation.

在本文中，我们提出了一种高度精确，完全安全的文档相似性搜索（FSDS）方案，该方案同时利用了安全性的一种新颖变体 $ķ$-NN算法和某种同态加密（SWHE）。该方案提供数据，查询和搜索模式隐私，并且适合访问模式隐私。我们提供原始安全保护和新安全保护的正式安全分析$ķ$-NN算法并显示后者是IND-CPA安全的。我们还依靠SWHE计划的IND-CPA安全性来满足强烈的隐私声明。与仅使用SWHE的方案相比，该方案提供了大约两个数量级的加速，而其整体性能与具有较弱形式的隐私声明的文献中的其他方案相当（并且在某些情况下更快）。我们介绍了实现结果，包括来自与响应时间，存储和带宽要求有关的文献的结果，并表明所提出的方案有助于实现轻量级客户端实现。