论文标题
关于基于代码的单服务器计算PIR方案的隐私
On the privacy of a code-based single-server computational PIR scheme
论文作者
论文摘要
我们表明，Holzbaur，Hollanti和Wachter-Zeh在2020年提出的单服务器计算PIR协议不是私有的，从某种意义上说，服务器可以在多项式时间内恢复所需文件的索引，具有很高的可能性。攻击取决于以下观察。与所需文件相对应的查询矩阵的行删除行会大大降低尺寸，超过$ \ mathbb {f} _q $的矢量空间，该矢量空间由此刺穿矩阵的行跨越。当删除与请求的文件无关的行时，这种维度损失仅显示出可忽略的概率。
We show that the single-server computational PIR protocol proposed by Holzbaur, Hollanti and Wachter-Zeh in 2020 is not private, in the sense that the server can recover in polynomial time the index of the desired file with very high probability. The attack relies on the following observation. Removing rows of the query matrix corresponding to the desired file yields a large decrease of the dimension over $\mathbb{F}_q$ of the vector space spanned by the rows of this punctured matrix. Such a dimension loss only shows up with negligible probability when rows unrelated to the requested file are deleted.
