Title
A Secure Location-based Alert System with Tunable Privacy-Performance Trade-off
Abstract
Monitoring location updates from mobile users has important applications in many areas, ranging from public health (e.g., COVID-19 contact tracing) and national security to social networks and advertising. However, sensitive information can be derived from movement patterns, thus protecting the privacy of mobile users is a major concern. Users may only be willing to disclose their locations when some condition is met, for instance in proximity of a disaster area or an event of interest. Currently, such functionality can be achieved usingsearchable encryption. Such cryptographic primitives provide provable guarantees for privacy, and allow decryption only when the location satisfies some predicate. Nevertheless, they rely on expensivepairing-based cryptography (PBC), of which direct application to the domain of location updates leads to impractical solutions. We propose secure and efficient techniques for private processing of location updates that complement the use of PBC and lead to significant gains in performance by reducing the amount of required pairing operations. We implement two optimizations that further improve performance: materialization of results to expensive mathematical operations, and parallelization. We also propose an heuristic that brings down the computational overhead through enlarging an alert zone by a small factor (given as system parameter), therefore trading off a small and controlled amount of privacy for significant performance gains. Extensive experimental results show that the proposed techniques significantly improve performance compared to the baseline, and reduce the searchable encryption overhead to a level that is practical in a computing environment with reasonable resources, such as the cloud.
Year
DOI
Venue
2020
10.1007/s10707-020-00410-1
GEOINFORMATICA
Keywords
DocType
Volume
Location privacy,Searchable encryption
Journal
24.0
Issue
ISSN
Citations 
4.0
1384-6175
0
PageRank 
References 
Authors
0.34
0
4
Name
Order
Citations
PageRank
Gabriel Ghinita1196487.44
Kien Nguyen242964.26
Mihai Maruseac375.31
Cyrus Shahabi45010411.59