Coded caching has been shown as a promissing method to reduce the network load in peak-traffic hours. In the coded caching literature, the notion of privacy is considered only against demands. On the motivation that multi-round transmissions almost appear everywhere in real communication systems, this paper formulates the coded caching problem with private demands and caches. Only one existing private caching scheme, which is based on introducing virtual users, can preserve the privacy of demands and caches simultaneously, but with an extremely large subpacketization exponential to the product of the numbers of users and files in the system. In order to reduce the subpacketization while satisfying the privacy constraint, we propose a novel approach which constructs private coded caching schemes through private information retrieval (PIR). Based on this approach, we propose novel schemes with private demands and caches which have a subpacketization level in the order exponential to $K$ (number of users) against $NK$ in the virtual user scheme where $N$ stands for the numbers of files. As a by-product, for the coded caching problem with private demands, a private coded caching scheme could be obtained from the proposed approach, which generally improves the memory-load tradeoff of the private coded caching scheme by Yan and Tuninetti.
翻译:代码缓存已被显示为减少高峰交易时数网络负荷的期货方法。 在编码缓存文献中,隐私的概念只根据需求来考虑。关于多轮传输几乎在真实通信系统中到处出现的动机,本文用私人需求和缓存方式提出了编码缓存问题。只有一个以引入虚拟用户为基础的现有私人缓存办法可以同时保存需求和缓存的隐私,但有一个非常大的子包装指数,以达到系统中用户和文件数量的产品。为了减少子包装,同时满足隐私限制,我们提出了一个新颖办法,通过私人信息检索(PIR)来建立私人编码缓存计划。基于这一办法,我们提出了私人需求和缓存问题的新办法,其次包装水平以引入虚拟用户用户为单位,以美元为单位,以美元为单位,用美元作为子包装,用美元标出系统中的文档数量。为了减少子包装,我们提出了一个新办法,通过私人信息检索(PIR)建立私人编码缓存计划,用私人代码改进了私人交易计划,以总体存储方式改进了纸质交易计划。