III: Small: Collaborative Research: PE4GQ - Practical Encryption for Geospatial Queries on Private Data

移动计算革命导致了以地理空间数据为中心的新颖和令人兴奋的应用的出现，如基于位置的服务、地理社交网络和拼车。这些应用程序使用户能够接收针对其位置定制的服务，并与附近的同行互动。然而，近年来也见证了与位置数据共享相关的越来越多的风险。利用位置信息，对手可能发动广泛的攻击，从物理监视和跟踪，到推断个人的私人细节-S的健康状况、政治或宗教背景、替代生活方式等。拟议的项目将调查安全和高效的技术，以在移动用户被发送到在线服务之前保护他们的位置。重点将放在加密上，它提供了高级别的保护，与目前用于社保号和银行账户信息等机密数据的加密级别相同。位置隐私是更广泛的在线隐私概念的重要组成部分。为用户提供强有力的保护？在当前的在线生态系统中，下落将带来显著的社会效益。在当前的在线生态系统中，隐私攻击发生得比以前更频繁，影响也更大，最近影响到社交媒体行业知名参与者(如谷歌、Facebook、雅虎)的高调隐私泄露事件就证明了这一点。之前的几项研究工作侧重于通过位置伪装、差异隐私或地理不可分辨等机制来保护位置，但这些现有方法都不能很好地应对在线、持续共享位置的挑战。实现足够数量保护的唯一方向是加密方法，但尽管最近在功能加密领域取得了突破，但对加密数据的处理非常缓慢和/或表达能力不足，无法支持以位置为中心的应用程序所需的用例场景。该项目的目标是弥合地理空间应用和功能加密之间的差距。拟议的PE4GQ(地理空间查询的实用加密)框架将允许研究人员和实践者使用加密的地理空间数据搜索原语，具有实际的计算和通信开销。该项目将采用现有的功能加密技术，并根据地理空间查询的具体要求定制其使用。该项目将解决几项具有挑战性的任务：(1)确定在以位置为中心的应用程序中常见的、可用于表达更复杂的空间查询的一小组代表性明文操作；(2)确定可用于安全地评估第一个任务中所确定的操作的适当的密码构建块；(3)调查通过减少昂贵的密码原语的数量而允许进行高效安全评估的数据表示和查询编码；以及(Iv)研究通过考虑来自空间域的信息(即，通过跨层设计)来减少加密数据处理开销的性能优化。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The mobile computing revolution led to the emergence of novel and exciting applications centered on geospatial data, such as location-based services, geosocial networks, and ride-sharing. These apps enable users to receive services customized to their locations and to interact with nearby peers. However, recent years also witnessed a growing number of risks associated with sharing of location data. Using location information, adversaries may stage a broad spectrum of attacks, ranging from physical surveillance and stalking, to inferring private details about an individual?s health status, political or religious affiliations, alternative lifestyles, etc. The proposed project will investigate secure and efficient techniques to protect the locations of mobile users before they are sent to online services. The focus will be on encryption, which provides a high level of protection, on the same level currently used for confidential data such as social security numbers and bank account information. Location privacy is an important component of the broader online privacy concept. Strong protection for users? whereabouts will bring significant societal benefits in the current online ecosystem, where privacy attacks occur more frequently and with far greater ramifications than before, as illustrated by recent high-profile privacy breaches that affected prominent players in the social media industry (e.g., Google, Facebook, Yahoo).Several prior research efforts focused on protecting locations through mechanisms like location cloaking, differential privacy or geo-indistinguishability, but none of these existing approaches can properly address the challenges of online, continuous sharing of locations. The only direction that achieves a sufficient amount of protection is represented by cryptographic approaches, but despite recent breakthroughs in the area of functional encryption, processing on encrypted data is very slow and/or insufficiently expressive to support the use case scenarios required by location-centric applications. The objective of this project is to bridge the gap between geospatial applications on one side and functional encryption on the other. The proposed PE4GQ (Practical Encryption for Geospatial Queries) framework will allow researchers and practitioners to make use of encrypted search primitives on geospatial data with practical computational and communication overhead. The project will adopt existing functional encryption techniques and customize their use to the specific requirements of geospatial queries. The project will address several challenging tasks: (i) identifying a small set of representative plaintext operations that occur commonly in location-centric applications and can be used to express more complex spatial queries; (ii) identifying appropriate cryptographic building blocks that can be used to securely evaluate the operations identified in the first task; (iii) investigating data representations and query encodings that allow efficient secure evaluation by reducing the number of expensive cryptographic primitives; and (iv) investigating performance optimizations that reduce encrypted data processing overhead by taking into account information from the spatial domain (i.e., through cross-layer design).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.