LASTor: A Low-Latency AS-Aware Tor Client
LASTor: A Low-Latency AS-Aware Tor Client
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DOI：
10.1109/tnet.2013.2291242
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发表时间：
2014-12-01
影响因子：
3.7
通讯作者：
Madhyastha, Harsha V.
中科院分区：
文献类型：
--
作者：
Akhoondi, Masoud;Yu, Curtis;Madhyastha, Harsha V.
虽然广泛使用的Tor匿名网络旨在实现低延迟匿名通信，但Tor上的交互式通信比直接互联网路径上的延迟高5倍以上，并且在许多情况下，自治系统（AS）可以通过网络流量的相关性来损害匿名性。在本文中，我们开发了LASTor，这是一个新的Tor客户端，仅通过客户端修改即可解决Tor中的这些缺点。首先，LASTor通过在选择路径时考虑Tor中继的推断位置来改善通信延迟。由于对较短路径的偏好降低了路径选择的熵，因此我们设计了LAST或，以便用户可以在延迟和匿名性之间选择适当的权衡。其次，我们开发了一种高效且准确的算法来识别AS可能通过流量相关性损害匿名性的路径。LASTor避免了这样的路径，以提高用户的匿名性，并且该算法的低运行时间确保了对端到端通信延迟的影响很低。我们的研究结果表明，与默认的Tor客户端相比，LASTor将中值延迟降低了25%，同时将未检测到潜在窥探AS的假阴性率从57%降低到11%。
Though the widely used Tor anonymity network is designed to enable low-latency anonymous communication, interactive communications on Tor incur latencies over 5x greater than on the direct Internet path, and in many cases, autonomous systems (ASs) can compromise anonymity via correlations of network traffic. In this paper, we develop LASTor, a new Tor client that addresses these shortcomings in Tor with only client-side modifications. First, LASTor improves communication latencies by accounting for the inferred locations of Tor relays while choosing paths. Since the preference for shorter paths reduces the entropy of path selection, we design LASTor so that a user can choose an appropriate tradeoff between latency and anonymity. Second, we develop an efficient and accurate algorithm to identify paths on which an AS can compromise anonymity by traffic correlation. LASTor avoids such paths to improve a user's anonymity, and the low run-time of the algorithm ensures that the impact on end-to-end communication latencies is low. Our results show that, in comparison to the default Tor client, LASTor reduces median latencies by 25% while also reducing the false negative rate of not detecting a potential snooping AS from 57% to 11%.