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团体之间的面对面交流一样普遍。 虽然已知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组对话方面存在差距。 该项目正在开发新的通信技术和开放源码软件，用于用户群体之间的私人通信。 这些技术和软件使新的远距离通信和协作在隐私是重要的情况下，这将有利于社会，通过允许群体通信，而不与广告商和数据经纪人分享他们的私人数据。虽然已知的几个协议，可以提供强有力的隐私保护两方对话，很少有人了解私人群体对话的属性。特别是，无论是像Signal这样的部署协议，还是像多方OTR和GOTR这样的学术协议，都不能保证组对话中的参与者对消息集、消息顺序甚至对话中的其他参与者列表保持一致的看法。 与此同时，可靠的广播协议可以提供这些一致性属性，但没有相同的隐私目标，携带沉重的带宽开销，并不适合部署在现代网络环境中，本项目正在开发新的算法和软件，以缩小这种差距之间的部署私人，两方通信计划和高开销，可靠的组通信原语。 它有三个具体目标：1。通过将两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的定义，可证明安全的协议，以及在现实网络设置中用于私人组消息传递的软件。为了实际进行私人群组对话，消息传递软件必须支持多个附加功能，同时保护隐私。此外，核心通信和这些附加功能都必须是可用的，因为用户可以理解并根据实现提供的有关这些协议的信息采取行动。 该项目正在为这些任务开发和实施协议，同时研究这些协议和实施的可用性。除了群组消息传递之外，该项目正在调查其他群组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，并调整前两个工具以解决这些设置。该项目预计将导致新的有效算法的私人团体通信和支持任务，本科生和研究生的培训，并广泛传播的自由软件，促进私人团体communication.This奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。

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.