SaTC: CORE: Small: Customizable Geo-Obfuscation to Protect Users' Location Privacy in Mobile Crowdsourcing

地理混淆是一种隐私保护技术，允许用户在基于位置的应用（如移动的众包）中报告混淆的位置，而不是他们的精确位置。虽然地理混淆提供了强大的隐私保证，但由于混淆而出现的位置错误可能会影响服务质量。目前对该主题的研究主要集中在通过优化技术最大限度地减少质量损失，但由于高计算开销，它仅限于少数位置。因此，现有的工作限制的范围内的地理混淆，无论是在大规模区域的低粒度或高粒度的小规模区域，留给用户的空间来定制他们的特定需求的地理混淆。该项目的创新之处在于设计了一个以用户为中心的多粒度、多尺度的地理混淆算法，可以根据用户的不同需求进行定制。所提出的研究显着提高了现有的地理混淆技术的灵活性和可扩展性，从而推进其在各种移动的背景下的应用。该项目更广泛的意义和重要性是积极影响许多先进的众包应用程序的广泛采用，同时确保个人隐私。此外，该项目的教育工作包括课程开发、K-12外联活动以及代表性不足的学生参与研究。首先，该项目设计了具有时间效率的算法，能够计算各种位置粒度和规模的地理混淆，覆盖了包括县、城市、街道、建筑物和房间在内的数百万个位置。其次，在已开发的地理混淆算法的基础上，该项目旨在根据大量移动的用户的需求定制地理混淆，考虑到他们不同的移动特性和不同场景的上下文信息。最后，该项目确定了各种粒度级别的可定制地理混淆的潜在威胁。根据从威胁模型中获得的见解，该项目设计了更好地保护用户位置隐私免受新威胁的对策。该奖项反映了NSF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。

Geo-obfuscation is a privacy protection technique that allows users to report obfuscated locations instead of their precise locations in location-based applications such as mobile crowdsourcing. While geo-obfuscation offers strong privacy guarantees, the location errors that arise due to obfuscation can affect the quality of the service. Current research on this topic focuses on minimizing quality loss through optimization techniques, but due to the high computation overhead, it is limited to a small number of locations. Consequently, existing works restrict the scope of geo-obfuscation to either low granularity in a large-scale region or high granularity in a small-scale region, leaving little room for users to customize geo-obfuscation to their specific requirements. The project's novelties are to design a user-centric geo-obfuscation in multi-granularity and multi-scale, which can be customized based on users' diverse demands. The proposed research significantly enhances the flexibility and scalability of existing geo-obfuscation techniques, thereby advancing their application in various mobile contexts. The project's broader significance and importance are to positively impact the wide adoption of many advanced crowdsourcing applications while ensuring individual privacy. In addition, the educational efforts of this project encompass curriculum development, K-12 outreach activities, and the engagement of underrepresented students in research.The project comprises three research tasks. Firstly, the project designs time-efficient algorithms capable of calculating geo-obfuscation for a wide range of location granularity and scales, covering millions of locations in a hierarchy that includes counties, cities, streets, buildings, and rooms. Secondly, based on the developed geo-obfuscation algorithms, the project aims to customize geo-obfuscation according to the demands of a large group of mobile users, taking into account their diverse mobility features and contextual information across different scenarios. Finally, the project identifies potential threats to customizable geo-obfuscation at various granularity levels. On the basis of the insights gained from the threat models, the project designs countermeasures to better protect users' location privacy against the new threats.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.