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arXiv 1602.09134cs.ITcs.CRcs.IRmath.IT
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私有信息检索容量

The Capacity of Private Information Retrieval

Hua Sun, Syed A. Jafar

摘要:

在专用信息检索(PIR)问题中,用户希望尽可能有效地从$N$非通信数据库(每个数据库保存所有$K$消息)中检索出$K$消息中的一个,同时不向任何单独的数据库透露任何关于所需消息索引的标识。PIR的信息理论容量是每比特下载信息可以私下检索的所需信息的最大比特数。对于$K$消息和$N$数据库,我们证明了PIR容量是$(1+1/N+1/N^2+\cdots+1/N^{K-1})^{-1}$。容量实现方案的显著特征是,如果我们消除消息的任何子集(通过将消息符号设置为零),则所得到的方案也实现了消息的剩余子集的PIR容量。

英文摘要:

In the private information retrieval (PIR) problem a user wishes to retrieve, as efficiently as possible, one out of $K$ messages from $N$ non-communicating databases (each holds all $K$ messages) while revealing nothing about the identity of the desired message index to any individual database. The information theoretic capacity of PIR is the maximum number of bits of desired information that can be privately retrieved per bit of downloaded information. For $K$ messages and $N$ databases, we show that the PIR capacity is $(1+1/N+1/N^2+\cdots+1/N^{K-1})^{-1}$. A remarkable feature of the capacity achieving scheme is that if we eliminate any subset of messages (by setting the message symbols to zero), the resulting scheme also achieves the PIR capacity for the remaining subset of messages.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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