SaTC: CORE: Small: Consistent and Private Group Communication

短信和基于社交媒体的消息应用程序已经变得几乎和个人和群体之间面对面的交流一样普遍。虽然我们知道如何为两个人之间的对话提供隐私，但在将这些技术扩展到群体对话方面还存在差距。这个项目正在开发新的通信技术和开源软件，用于用户群体之间的私人通信。这些技术和软件在隐私重要的情况下实现了新的远程通信和协作，这将使社会受益，因为它允许团体在不与广告商和数据经纪人分享他们的私人数据的情况下进行通信。虽然已知有几个协议可以为双方对话提供强大的隐私保护，但对私有组对话的属性了解较少。特别是，无论是Signal这样的已部署协议，还是多方OTR和GOTR这样的学术协议，都不能保证组会话中的参与者保持对消息集、消息顺序甚至会话中其他参与者列表的一致视图。与此同时，可靠的广播协议可以提供其中的一些一致性属性，但不具有相同的隐私目标，携带沉重的带宽开销，并且不适合在现代网络环境中部署。该项目正在开发新的算法和软件，以缩小可部署的私有、双方通信方案和高开销、可靠的组通信原语之间的差距。它有三个具体目标：1。通过将双方隐私概念扩展到组上下文，并将可靠的广播要求放宽到一致性形式主义，该项目正在开发正式定义，可证明的安全协议，以及在现实网络设置中用于私人组消息传递的软件。为了实际执行私人群组对话，消息传递软件必须在保护隐私的同时支持几个额外的功能。此外，核心通信和这些附加功能都必须是可用的，因为用户可以理解实现提供的关于这些协议的信息并对其进行操作。该项目正在为这些任务开发和实现协议，同时研究这些协议和实现的可用性。除了群发消息之外，该项目还在研究其他群发设置中的隐私和一致性概念，例如语音和视频通信、半公开论坛和封闭邮件列表，并调整前两个目标中的工具来解决这些设置。该项目预计将产生新的有效算法，用于私人群体通信和支持任务，培训本科生和研究生，以及广泛传播促进私人群体通信的自由软件。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Texting and social media-based messaging applications have become nearly as common as face-to-face communications for conversation between individuals and groups. While it is known how to provide privacy for conversations between two individuals, there is a gap in extending these techniques to group conversations. This project is developing new communication techniques and open-source software for private communication among groups of users. These techniques and software enable new long-distance communication and collaboration in situations where privacy is important, which will benefit society by allowing groups to communicate without sharing their private data with advertisers and data brokers.While several protocols are known that can provide strong privacy protections for two-party conversations, less is understood about the properties of private group conversations. In particular, neither deployed protocols such as Signal, nor academic protocols such as multiparty OTR and GOTR, can guarantee that participants in a group conversation maintain a consistent view of the set of messages, order of messages, or even the list of fellow participants in the conversation. Meanwhile, reliable broadcast protocols can provide some of these consistency properties but do not have the same privacy goals, carry a heavy bandwidth overhead, and are ill-suited for deployment in the modern network environment.This project is developing new algorithms and software to close this gap between deployable private, two-party communication schemes and high-overhead, reliable group communication primitives. It has three specific aims:1. By extending two-party privacy notions to a group context, and relaxing reliable broadcast requirements to a consistency formalism, the project is developing formal definitions, provably secure protocols, and software for private group messaging in realistic network settings.2. In order to practically carry out private group conversations, messaging software must support several additional functionalities while preserving privacy. Furthermore, both the core communication and these additional functions mustbe usable, in that users can understand and act on the information about these protocolsprovided by the implementations. The project is developing and implementing protocols for these tasks, while studying the usability of these protocols and implementations.3. Beyond group messaging, the project is investigating notions of privacy and consistency in other group settings, such as voice and video communication, semi-public forums and closed mailing lists, and adapting the tools from the first two aims to address these settings. The project is expected to result in new efficient algorithms for private group communication and supporting tasks, training of undergraduate and graduatestudents, and the broad dissemination of free software that promotes private group communication.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.