Coded Caching in the Presence of a Wire and a Cache Tapping Adversary of Type II
Coded Caching in the Presence of a Wire and a Cache Tapping Adversary of Type II
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DOI：
10.1109/jsait.2021.3054663
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发表时间：
2021-03
期刊：
影响因子：
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通讯作者：
Mohamed S. Nafea;A. Yener
中科院分区：
文献类型：
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作者：
Mohamed S. Nafea;A. Yener
在编码缓存的信息理论模型中引入了缓存挖掘的概念。介绍了在配备固定大小缓存存储器的多个接收器存在下的窃听信道II，以及从缓存放置和/或传输中选择要窃听的符号的对手。合法的终端既不知道放置、传递或两者是否被监听，也不知道它们被监听的位置。只知道整个抽头集的大小。对于两个接收器和两个文件，确定了强保密能力——在保持整个库高度安全的情况下可实现的最大文件速率。当库中有两个以上的文件时，导出了强保密文件速率的下界和上界。可实现性依赖于结合了窃听编码、安全嵌入代码、一次性按键和编码缓存的代码设计。一个精灵辅助上界，在这个上界中，发射器在放置之前已经提供了用户的需求，建立了双档情况的相反情况。对于两个以上的文件，上界由三个连续的通道变换构造。我们的结果建立了可证明的安全保证，以防止强大的对手在缓存辅助系统中优化其在通信的两个阶段的窃听。
This paper introduces the notion of cache-tapping into the information theoretic models of coded caching. The wiretap channel II in the presence of multiple receivers equipped with fixed-size cache memories, and an adversary which selects symbols to tap into from cache placement and/or delivery is introduced. The legitimate terminals know neither whether placement, delivery, or both are tapped, nor the positions in which they are tapped. Only the size of the overall tapped set is known. For two receivers and two files, the strong secrecy capacity– the maximum achievable file rate while keeping the overall library strongly secure– is identified. Lower and upper bounds on the strong secrecy file rate are derived when the library has more than two files. Achievability relies on a code design which combines wiretap coding, security embedding codes, one-time pad keys, and coded caching. A genie-aided upper bound, in which the transmitter is provided with user demands before placement, establishes the converse for the two-files case. For more than two files, the upper bound is constructed by three successive channel transformations. Our results establish provable security guarantees against a powerful adversary which optimizes its tapping over both phases of communication in a cache-aided system.