论文标题
潜在可验证的私人信息检索
Latent-variable Private Information Retrieval
论文作者
论文摘要
在许多应用中,用户访问的内容(电影,视频,新闻文章等)可以泄露敏感的潜在属性,例如宗教和政治观点,性取向,种族,性别,性别等。为了防止此类信息泄漏,经典PIR的目标是隐藏要访问的内容/消息的身份,随后还隐藏了潜在属性。该解决方案虽然私有,尤其是在施加完美(信息理论)隐私限制时。例如,对于持有$ K $消息的单个数据库,私下检索一条消息是可能的,并且仅当用户下载$ k $消息的整个数据库时。但是,可以私下检索内容可以完美隐藏潜在属性。 在上述激励的情况下,我们制定和研究潜在可变量的私人信息检索(LV-PIR)的问题,该问题旨在允许用户有效地检索$ k $消息中的一个($θ$索引),而无需透露任何有关潜在变量的信息(由$ s $模型)。我们专注于单个数据库的实际相关设置,并表明,基于$θ$和$ s $之间的相关性,可以显着降低LV-PIR的下载成本(与经典PIR相比)。我们提出了LV-PIR的一般方案,这是$θ$和$ s $之间的统计关系的函数,还为LV-PIR的容量/下载成本提供了新的结果。还讨论了几个开放问题和新方向。
In many applications, content accessed by users (movies, videos, news articles, etc.) can leak sensitive latent attributes, such as religious and political views, sexual orientation, ethnicity, gender, and others. To prevent such information leakage, the goal of classical PIR is to hide the identity of the content/message being accessed, which subsequently also hides the latent attributes. This solution, while private, can be too costly, particularly, when perfect (information-theoretic) privacy constraints are imposed. For instance, for a single database holding $K$ messages, privately retrieving one message is possible if and only if the user downloads the entire database of $K$ messages. Retrieving content privately, however, may not be necessary to perfectly hide the latent attributes. Motivated by the above, we formulate and study the problem of latent-variable private information retrieval (LV-PIR), which aims at allowing the user efficiently retrieve one out of $K$ messages (indexed by $θ$) without revealing any information about the latent variable (modeled by $S$). We focus on the practically relevant setting of a single database and show that one can significantly reduce the download cost of LV-PIR (compared to the classical PIR) based on the correlation between $θ$ and $S$. We present a general scheme for LV-PIR as a function of the statistical relationship between $θ$ and $S$, and also provide new results on the capacity/download cost of LV-PIR. Several open problems and new directions are also discussed.