论文标题
使用PDA的高速缓存多用户私人信息检索
Cache-Aided Multi-User Private Information Retrieval using PDAs
论文作者
论文摘要
我们考虑缓存的多用户私人信息检索（Mupir）的问题。在此问题中，$ n $独立文件将在$ s \ geq 2 $非胶卷服务器上复制。有$ k $的用户，每个用户都配备了可以存储$ m $文件的缓存内存。每个用户都想从服务器检索文件，但是用户不希望任何服务器都能获取有关其需求的任何信息。用户缓存填充了文件的某些任意函数，然后用户决定其需求（称为放置阶段）。在确定需求之后，用户合作向服务器发送查询，以私下检索其所需的文件。收到查询后，服务器广播了编码的传输，这些变速箱函数是他们收到的查询和文件（称为交付阶段）的函数。将查询传达给服务器会为用户上传成本，并下载由服务器广播的答案会导致下载成本。要实现高速缓存的Mupir方案，每个文件都必须分为$ f $ take。在本文中，我们提出了利用放置递送阵列（PDA）来表征放置和交付的穆皮尔方案。拟议的Mupir计划可显着降低子包装水平，同时略微增加下载成本。拟议的计划还大大降低了用户的上传成本。对于基于{\ it ali-niesen的PDA，用于集中编码的缓存方案，我们表明我们的方案在下载成本方面是最佳的订单。我们恢复{\ it tian等人}提出的最佳单用户PIR方案作为一种特殊情况。我们的方案还实现了R. Tondon报告的单用户高速缓存PIR设置的最佳速率。
We consider the problem of cache-aided multi-user private information retrieval (MuPIR). In this problem, $N$ independent files are replicated across $S \geq 2$ non-colluding servers. There are $K$ users, each equipped with cache memory which can store $M$ files. Each user wants to retrieve a file from the servers, but the users don't want any of the servers to get any information about their demand. The user caches are filled with some arbitrary function of the files before the users decide their demands, known as the placement phase. After deciding their demands, users cooperatively send queries to the servers to retrieve their desired files privately. Upon receiving the queries, servers broadcast coded transmissions which are a function of the queries they received and the files, known as the delivery phase. Conveying queries to the servers incurs an upload cost for the users, and downloading the answers broadcasted by the servers incurs a download cost. To implement cache-aided MuPIR schemes, each file has to be split into $F$ packets. In this paper, we propose MuPIR schemes that utilize placement delivery arrays (PDAs) to characterize placement and delivery. Proposed MuPIR schemes significantly reduce subpacketization levels while slightly increasing the download cost. The proposed scheme also substantially reduces the upload cost for the users. For PDAs based on {\it Ali-Niesen} scheme for centralized coded caching, we show that our scheme is order optimal in terms of download cost. We recover the optimal single-user PIR scheme presented by {\it Tian et al.} as a special case. Our scheme also achieves optimal rate for single-user cache-aided PIR setup reported by R. Tondon.
