Understanding Tor Usage with Privacy-Preserving Measurement
Understanding Tor Usage with Privacy-Preserving Measurement
复制标题
通过隐私保护测量了解 Tor 的使用情况
DOI：
10.1145/3278532.3278549
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
M. Sherr
中科院分区：
文献类型：
--
作者：
A. Mani;T. Wilson;Rob Jansen;Aaron Johnson;M. Sherr
Tor匿名网络很难测量，因为如果不仔细进行测量，可能会危及网络用户的隐私(以及潜在的安全)。最近的工作提出了使用差异隐私和安全聚合技术来安全地测量ToR，并开发了初步的概念验证原型工具来演示这些技术的实用性。在这项工作中，我们显著增强了两个这样的工具-PrivCount和Private Set-Union Cardinality--以支持对以前从未测量过的新型ToR使用行为的安全探索。使用增强的工具，我们对Tor进行了详细的测量研究，涵盖了Tor使用的三个主要方面：有多少用户连接到Tor，他们从哪里连接，用户最频繁地与哪些目的地通信，以及存在多少洋葱服务和如何使用这些服务。我们的发现包括，Tor每天有大约800万用户，比之前认为的多4倍。我们还发现，通过Tor访问的网站中，约40%的网站拥有torject.org域名，约10%的网站拥有Amazon.com域名，约80%的网站的域名跻身Alexa TOP 100万网站排行榜。最后，我们发现大约90%的洋葱地址查找是无效的，90%以上的洋葱服务尝试连接失败。
The Tor anonymity network is difficult to measure because, if not done carefully, measurements could risk the privacy (and potentially the safety) of the network's users. Recent work has proposed the use of differential privacy and secure aggregation techniques to safely measure Tor, and preliminary proof-of-concept prototype tools have been developed in order to demonstrate the utility of these techniques. In this work, we significantly enhance two such tools---PrivCount and Private Set-Union Cardinality---in order to support the safe exploration of new types of Tor usage behavior that have never before been measured. Using the enhanced tools, we conduct a detailed measurement study of Tor covering three major aspects of Tor usage: how many users connect to Tor and from where do they connect, with which destinations do users most frequently communicate, and how many onion services exist and how are they used. Our findings include that Tor has ~8 million daily users, a factor of four more than previously believed. We also find that ~40% of the sites accessed over Tor have a torproject.org domain name, ~10% of the sites have an amazon.com domain name, and ~80% of the sites have a domain name that is included in the Alexa top 1 million sites list. Finally, we find that ~90% of lookups for onion addresses are invalid, and more than 90% of attempted connections to onion services fail.