TWC: Option: Medium: Measurement-Based Design and Analysis of Censorship Circumvention Schemes

互联网已经成为最有效和最常见的表达方式之一，这些表达方式可能会引起争议或被压制。这种言论自由受到现在普遍存在的私人和国家利益互联网审查的威胁。Tor网络是几种工具之一，旨在允许用户通过一台或多台中继计算机安全高效地访问被审查的内容。使用这些中继器，审查员很难确定哪些内容被谁访问。不幸的是，这也使得很难衡量这些工具的使用和性能，导致在评估工具的影响以及建议的替代方案的安全性和性能方面面临挑战。该项目正在开发协议和软件来应对这些挑战，以解决三个具体目标：1.开发和部署加密协议，以安全和私密地测量和发布ToR网络动态的重要特征，包括：随时间推移的用户数、用户正常运行时间和停机时间分布、用户流失、网络负载和退出统计数据。2.增强ToR的安全性和性能，使用收集的数据来改进评估。改进规避中继拦截的通用方法，包括代理分发方案、协议隐写和诱骗路由。该项目预计将产生广泛使用的数据集，用于评估审查规避方案，培训本科生和研究生，并广泛传播促进互联网言论自由的自由软件，对抗强烈反对此类言论的政权。

The Internet has become one of the most effective and common means of conveying expression that is likely to be controversial or suppressed. This freedom of expression is threatened by the now widespread practice of Internet censorship by both private and state interests.The Tor network is one of several tools designed to allow users to safely and efficiently access censored content through one or more relay computers. Using these relays makes it difficult for a censor to determine what content is being accessed by whom. Unfortunately, this also makes it hard to measure the use and performance of these tools, leading to challenges in assessing the impact of the tools, and the security and performance of proposed alternatives.This project is developing protocols and software to address these challenges, addressing three specific aims:1. Developing and deploying cryptographic protocols that safely and privately measure and release important characteristics of the dynamics of the Tor network, including: number of users over time, user uptime and downtime distributions, user churn, network load, and exit statistics. 2. Enhancing the security and performance of Tor, using the data collected to improve evaluations.3. Improving generic methods to circumvent relay blocking, including proxy distribution schemes, protocol steganography, and decoy routing.The project is expected to result in widely-used datasets for evaluating censorship circumvention schemes, training of undergraduate and graduate students, and broad dissemination of free software that promotes freedom of expression on the Internet, against regimes that strongly oppose such expression.