论文标题
数字盲盒：随机对称私人信息检索
Digital Blind Box: Random Symmetric Private Information Retrieval
论文作者
论文摘要
我们介绍了随机对称私人信息检索（RSPIR）的问题。在Canonical PIR中，用户从$ n $ noncolluding和Replicated数据库中下载消息以$ K $消息的方式下载，以至于没有数据库可以知道用户已下载的哪个消息（用户隐私）。在SPER中，隐私是对称的，因为这不仅是数据库不知道用户已下载的哪个消息，而且用户本身不能比下载的特定消息（数据库隐私）进一步学习任何东西。在Rspir与SPIR不同的Rspir中，用户没有数据库的输入，即用户没有选择要下载的特定消息，而是与任何一条消息的内容内容。在rspir中，数据库需要以确保用户正确下载消息（随机可靠性）的方式向用户发送符号，数据库不知道用户已收到的消息（用户隐私），并且用户没有比收到的一条消息（数据库隐私）进一步学习任何东西。这是一个盲盒的数字版本，也称为Gachapon，它在上面指定的设置中使用物理对象进行娱乐。这也是$ 1 $ -Out-of-of $ k $ oblevious Transper（OT）的盲目版本，这是一个重要的加密原始版本。我们研究$ n = 2 $数据库的RSPIR的信息理论能力。我们确定其$ k = 2、3、4 $消息的确切能力。虽然我们提供了适用于任意数量消息的一般可实现的计划，但$ k \ geq 5 $的容量仍然开放。
We introduce the problem of random symmetric private information retrieval (RSPIR). In canonical PIR, a user downloads a message out of $K$ messages from $N$ non-colluding and replicated databases in such a way that no database can know which message the user has downloaded (user privacy). In SPIR, the privacy is symmetric, in that, not only that the databases cannot know which message the user has downloaded, the user itself cannot learn anything further than the particular message it has downloaded (database privacy). In RSPIR, different from SPIR, the user does not have an input to the databases, i.e., the user does not pick a specific message to download, instead is content with any one of the messages. In RSPIR, the databases need to send symbols to the user in such a way that the user is guaranteed to download a message correctly (random reliability), the databases do not know which message the user has received (user privacy), and the user does not learn anything further than the one message it has received (database privacy). This is the digital version of a blind box, also known as gachapon, which implements the above specified setting with physical objects for entertainment. This is also the blind version of $1$-out-of-$K$ oblivious transfer (OT), an important cryptographic primitive. We study the information-theoretic capacity of RSPIR for the case of $N=2$ databases. We determine its exact capacity for the cases of $K = 2, 3, 4$ messages. While we provide a general achievable scheme that is applicable to any number of messages, the capacity for $K\geq 5$ remains open.
