Your choice MATor(s) : large-scale quantitative anonymity assessment of Tor path selection algorithms against structural attacks
Your choice MATor(s) : large-scale quantitative anonymity assessment of Tor path selection algorithms against structural attacks
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您选择的 MATor(s) ：针对结构性攻击的 Tor 路径选择算法的大规模定量匿名评估
DOI：
10.22028/d291-26639
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
Marcin Slowik
中科院分区：
文献类型：
--
作者：
M. Backes;Sebastian Meiser;Marcin Slowik
在本文中，我们提出了一种严格的方法来量化Tor针对各种结构性攻击提供的匿名性，即，攻击者破坏Tor节点，从而进行窃听攻击，以使Tor用户匿名化。首先，我们提供了一种算法方法来计算这种结构化攻击对Tor的匿名性影响。该算法在所考虑的路径选择算法中是参数化的，因此能够推理Tor的变体和替代路径选择算法。其次，我们提出了形式化的各种实例的结构攻击Tor和计算的匿名性的影响，这些对手确实构成了一个最坏情况下的匿名性限制Tor的加密实现。第三，我们使用我们的方法来进行严格的，大规模的评估Tor的匿名性，建立最坏情况下的匿名边界对各种结构性攻击Tor和替代路径选择算法，如Distributor，SelekTOR和LASTor。这就产生了第一个严格的匿名不同的路径选择算法之间的比较。作为我们分析的一部分，我们量化了路径选择过渡阶段的匿名影响，即，少数用户决定运行替代算法，而绝大多数用户仍然使用原始算法。我们实现的源代码是公开的。
In this paper, we present a rigorous methodology for quantifying the anonymity provided by Tor against a variety of structural attacks, i.e., adversaries that corrupt Tor nodes and thereby perform eavesdropping attacks to deanonymize Tor users. First, we provide an algorithmic approach for computing the anonymity impact of such structural attacks against Tor. The algorithm is parametric in the considered path selection algorithm and is, hence, capable of reasoning about variants of Tor and alternative path selection algorithms as well. Second, we present formalizations of various instantiations of structural attacks against Tor and show that the computed anonymity impact of each of these adversaries indeed constitutes a worst-case anonymity bound for the cryptographic realization of Tor. Third, we use our methodology to conduct a rigorous, largescale evaluation of Tor’s anonymity which establishes worst-case anonymity bounds against various structural attacks for Tor and for alternative path selection algorithms such as DistribuTor, SelekTOR, and LASTor. This yields the first rigorous anonymity comparison between different path selection algorithms. As part of our analysis, we quantify the anonymity impact of a path selection transition phase, i.e., a small number of users decides to run an alternative algorithm while the vast majority still uses the original one. The source code of our implementation is publicly available.