论文标题
FlashFlow：TOR的安全速度测试
FlashFlow: A Secure Speed Test for Tor
论文作者
论文摘要
TOR网络使用测量系统来估计其继电器的转发能力并平衡它们之间的流量。该系统已被证明容易受到对抗操作的影响。此外，它在良性环境中的准确性和有效性从未得到充分量化。我们首先通过分析TOR指标数据并在实时网络上执行实验来获得这种量化。我们的结果表明，TOR目前低估了其真实容量约50％，并将其流量不当平衡15-25％。然后，为了解决安全性和准确性的问题，我们提出了闪存流量，该系统是测量TOR继电器能力的系统。我们的分析表明，FlashFlow将恶意继电器限制在获得其真实容量最多1.33倍的能力估计中。通过现实的Internet实验，我们发现FlashFlow测量能力至少为89％精度95％的时间。通过模拟，我们发现闪流可以使用3个带有1 GBIT/s带宽的测量器在不到5小时的时间内测量整个TOR网络。最后，使用FlashFlow进行负载平衡的模拟表明，与Torflow相比，网络重量误差降低了86％，而50 KIB，1 MIB和5 MIB的中位数分别降低了15％，29％和37％。此外，FlashFlow产生更一致的客户绩效：转移超时的中位数降低100％，而50 KIB，1 MIB和5 MIB转移时间的标准偏差分别降低了55％，61％和41％。我们还发现，随着客户交通拥堵负载的增加，相对于TORFLOW的增长相对于TORFLOW的增加，这表明FlashFlow更适合支持网络增长。
The Tor network uses a measurement system to estimate its relays' forwarding capacity and to balance traffic among them. This system has been shown to be vulnerable to adversarial manipulation. Moreover, its accuracy and effectiveness in benign circumstances has never been fully quantified. We first obtain such a quantification by analyzing Tor metrics data and performing experiments on the live network. Our results show that Tor currently underestimates its true capacity by about 50% and improperly balances its traffic by 15-25%. Then, to solve the problems with security and accuracy, we present FlashFlow, a system to measure the capacity of Tor relays. Our analysis shows that FlashFlow limits a malicious relay to obtaining a capacity estimate at most 1.33 times its true capacity. Through realistic Internet experiments, we find that FlashFlow measures relay capacity with at least 89% accuracy 95% of the time. Through simulation, we find that FlashFlow can measure the entire Tor network in less than 5 hours using 3 measurers with 1 Gbit/s of bandwidth each. Finally, simulations using FlashFlow for load balancing shows that, compared to TorFlow, network weight error decreases by 86%, while the median of 50 KiB, 1 MiB, and 5 MiB transfer times decreases by 15%, 29%, and 37%, respectively. Moreover, FlashFlow yields more consistent client performance: the median rate of transfer timeouts decreases by 100%, while the standard deviation of 50 KiB, 1 MiB, and 5 MiB transfer times decreases by 55%, 61%, and 41%, respectively. We also find that the performance improvements increase relative to TorFlow as the total client-traffic load increases, demonstrating that FlashFlow is better suited to supporting network growth.
