Privacy Enhancing Technologies for Censorship-resistant and Secure Internet Communications

在过去的几年中，互联网显著增加了由网站、消息传递应用程序和其他在线通信形式提供的安全和隐私技术的部署。然而，这些目前部署在隐私保护通信领域的技术只能解决部分问题。大多数方法侧重于保护消息的内容，但揭示了元数据(谁在何时何地与谁通信)。这类元数据允许重建一个人的社交网络、位置和活动，本身可能会泄露敏感信息，如属于少数群体或边缘化群体。此外，如果通信本身受到审查，而信息根本无法传播，那么保护通信内容和元数据的效用有限；国家范围的互联网审查在世界各地越来越普遍，严重损害了言论自由等人权。*互联网的原始设计没有考虑到政府部门操纵和审查通信，因此没有提供足够的机制来保证可用性：一个人可能希望使用的互联网服务实际上是可以访问的。同样，目前以数字方式共享的大量高度敏感的个人信息也没有得到充分的保护。对手，从轻微的罪犯到政府审查员，都能够观察和操纵互联网交流。这种监视和操纵既影响个人，例如由于个人信息泄露，也影响社会，例如由于全国范围的审查制度。因此，开发抵抗监视和审查的技术至关重要。*不幸的是，手动设计和评估用于安全和抗审查的通信的隐私增强技术(PETS)是繁琐的，而且众所周知很难完美地执行。此外，一个单一的设计缺陷可能会给用户带来灾难性的现实后果。通过实现自动化协议构建和验证，我们将确保未来对宠物的研究将更加高效，错误风险更低。*我们研究的长期目标是开发原创和创新的宠物，以克服现有最先进方法的限制，并提供更广泛的保护，使其免受监视和审查。根据上述讨论，我们确定了三个短期目标：i)保护通信元数据，ii)自动化协议建设，以及iii)抵抗审查的互联网接入。我们用于安全和抗审查通信的宠物解决了安全的所有三个传统方面：机密性、完整性和可用性。除了推进科学知识，我们还专注于部署我们的系统，使世界各地的用户受益。

In the last few years, the Internet has seen significantly increased deployment of security and privacy technologies offered by websites, messaging applications, and other forms of online communication. However, these currently deployed technologies in the area of privacy-preserving communication only solve part of the problem. Most approaches focus on protecting the contents of a message but reveal the metadata (who communicated with whom, when, and where). Such metadata allows the reconstruction of a person's social network, location, and activities, and by itself can reveal sensitive information such as being part of a minority or marginalized group. Furthermore, protecting communication contents and metadata is of limited utility if the communication itself is censored and the messages are not getting through at all; country-scale Internet censorship is increasingly common around the world, drastically undermining human rights such as freedom of speech.******The original design of the Internet did not account for governmental parties manipulating and censoring communication and hence does not provide adequate mechanisms to guarantee availability: that the Internet services one might wish to use are in fact reachable. Similarly, the abundance of sensitive highly personal information that is currently shared digitally is not adequately protected. Adversaries, ranging from petty criminals to governmental censors, are able to observe and manipulate Internet communication. Such surveillance and manipulation affects both individuals, for instance due to leaked personal information, as well as societies, for instance due to country-wide censorship. It is therefore essential to develop technologies to resist surveillance and censorship.******Unfortunately, manually designing and evaluating privacy-enhancing technologies (PETs) for secure and censorship-resistant communication is cumbersome and notoriously difficult to perform perfectly. Moreover, a single design flaw can lead to catastrophic real-world consequences for users. By enabling automated protocol construction and verification, we will ensure future research on PETs will be more efficient and have lower risk for errors.******The long-term goal of our research is to develop original and innovative PETs that overcome the limitations of the existing state-of-the-art approaches and provide more extensive protection from surveillance and censorship. In light of the above discussion, we identified three short-term goals: i) protecting communication metadata, ii) automated protocol construction, and iii) censorship-resistant Internet access. Our PETs for secure and censorship-resistant communication address all three traditional aspects of security: confidentiality, integrity, and availability. In addition to advancing scientific knowledge, we focus on deploying our systems to benefit users all over the world.